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Jack Pine
03-14-2012, 10:38 AM
I have been doing some mods to increase the performance of my Man Kung crossbow. For about $70, I increased the speed from 210fps to 264fps and KE from 39 to 44.5 ftlbs. I hope for a little more improvement. Not bad since the crossbow only cost $80 new. Other mods that aren’t performance related cost more, but those are custom-fit mods like the scope, flashlight, sling, stirrup, and redneck quiver I made. I can’t remember what the model of the MK is, but it’s one of the ones with the thumbhole stock and adjustable sight base like the dial-a-range. Since this site will only allow 5 pics per post, I’ll try to include the best ones.

The first mod you can make will cost about $50, and involves buying a 175lb prod [limb] from Arrow Precision that was made for their FURY model. It is identical in every respect to the 150lb prod the MK comes with EXCEPT that it is .030 thicker and considerably stiffer. This is a bolt-on mod; it actually uses the same limb tips as the MK and will also use the same string. I have it braced at about 3 ”, center of prod to center of string, but it is now about 3 1/8” after shooting yesterday. I will twist it back up to 3 ” next chance I get. At 3 ” brace, it is pulling a guestimated 180-200lb. This is giving me about a 10 3/8” power stroke.

The 210 fps was using a 400 grain 16” 2219 arrow tipped with a Scorpion XP mechanical head, delivering 39 ftlb of KE. About 30 ftlb KE is required to blow through the chest cavity of a deer, and that’s exactly what I got when I shot a little knobhead buck with it last season.

I was able to achieve an increase in performance by using a 2018 14” aluminum arrow weighing 288 grains. This increased the speed to 264fps and 44.5 ftlb of KE as I mentioned, but first a mod had to be made to the nose piece to allow the use of the smaller arrows. Some of you old vert compound users of years gone by will remember when “overdraws” first started being used on verts to allow shorter, lighter arrows to be used; this is the same principle. For $15 I had my local machine shop mill a “broadhead pocket” in the nosepiece to allow the use of the shorter, lighter 2018, while allowing the arrow to be fully supported by the rail, and without having the larger diameter of the broadhead raise the end of the arrow off the rail.

Another advantage of using the 2018 was the smaller diameter; [cuts the wind better and] it allows the use of flat nocks, since its center is lower to the rail, the center of the string almost exactly matches the center of the arrow. Since I can’t find 2018 crossbow nocks anywhere, I use a carbon insert; works good. Another slight increase in speed is due to the fletchings, they are duravane low profile vanes, only 1.8” long. The low profile keeps the vane from tipping the arrow when it crosses the prod in front, and it comes out straight, and the short length produces enough drag to steer it without slowing it down.

Some other mods are the 42mm 3x9 scope with the Butler Creek flip-up caps. I built the cheek piece up so that I can rest my cheek on the stock and look straight through the center of the scope.

Notice the redneck quiver, it holds 1 or 2 arrows on each side of the stock, and is a reminder to keep my fingers off the rail.

The aluminum rail has a dovetail groove underneath that allows a ” by 1/8” by about 3" piece of flat metal to slide into it, and I drilled and tapped it, mounted a Weaver scope base and used a high-rise scope mount to mount my 7 watt L.E.D. flashlight with, but it could also hold a laser or similar device.

The stirrup was removed and replaced with diamond-braid cord, removing the tuning fork effect and weight from the front end. The sling is merely a flat nylon strap attached by the prod bolt and the screw on the pistol grip.

The hollow buttstock holds a spare string, stringer, some matches, a tiny compass, and some spare limb tips, but not so they will rattle. Hope the pics help.

What I have done is made a lightweight, efficient, compact killing machine out of a crossbow that is not highly regarded by many, but it is the only crossbow I have now since I sold my Horton TRT UL. I will buy another crossbow when I find one I like better than the MK, but I’ve really grown to like it and I have the utmost confidence in its quick-kill capability as it’s now decked out. The only weakness it has is the excessive trigger travel, and one of these days, I’ll fix that too.

Jack ><>

Jack Pine
03-14-2012, 05:54 PM
YW, just holler if you need help with the mods.

Jack ><>

Jack Pine
03-19-2012, 10:01 AM
Friday I went to town and bought some 2018 XX75 Easton aluminum shafts and fletched up some arrows to shoot [get 2 arrows out of 1 shaft]. They weigh a little more than the ones I was shooting when I got 264 fps out of the MK. These weigh 296 and 298 grains, so they would be slightly slower. I twisted my string up to a 3 1/2" brace and started shooting. 260.5, 259.2, 259.2, 259.1, and 258.2 Checked the brace and it's holding at 3 1/4" so I guess it's done stretching and so now should shoot consistently around 258 fps or so. Really happy with that. Those Eastons fly really straight and pretty sweet.

Jack ><>

Mangyrat
05-03-2012, 05:45 AM
Jack I'm having problems finding a on-line seller of the 175lb prod [limb] from Arrow Precision FURY model.
Got a links to it?

The jaguar bow looks the same but i cant find parts for that bow either or i would order one and try that.
I even hit Ebay with no luck.

Jack Pine
05-03-2012, 09:41 AM
Jack I'm having problems finding a on-line seller of the 175lb prod [limb] from Arrow Precision FURY model.
Got a links to it?

The jaguar bow looks the same but i cant find parts for that bow either or i would order one and try that.
I even hit Ebay with no luck.

Rat, sent you a PM that should help.

Jack ><>

Mangyrat
05-03-2012, 05:55 PM
Thank you.

Boosbuddy
05-18-2012, 08:07 PM
Jack,
Great post on the MK crossbow. I just have a question: You state that you used a carbon insert in place of a flat nock on the 2018 14" bolt. What kind of insert and where did you get it? I am trying to find flat nocks for my 2018s as well and am having no luck at all.
Thanks for your help.
Bill

Jack Pine
05-19-2012, 09:10 AM
Jack,
Great post on the MK crossbow. I just have a question: You state that you used a carbon insert in place of a flat nock on the 2018 14" bolt. What kind of insert and where did you get it? I am trying to find flat nocks for my 2018s as well and am having no luck at all.
Thanks for your help.
Bill

Howdy Bill, welcome to Crossbow Forum! I bought the carbon inserts off ebay; I searched for 2018 carbon inserts if I remember correctly. You could also use aluminum inserts for flat nocks, but since aluminum is a little heavier than the carbon, it adds a little more weight to the tip of the arrow. This increases the weight-forward-of-center ratio, putting it around 12% with the mechanical broadheads I use; again if I remember correctly. Bottom line: they fly like bullets. BTW, I haven't been able to find crossbow nocks of any kind for the 2018, so the insert works well.

Jack ><>

Boosbuddy
05-19-2012, 03:01 PM
Thanks Jack!!

kamont
05-28-2012, 06:39 PM
Hi Jack
Was reading about your mods, was wondering why you are replacing the 150 lb limbs for the 175 lb as opposed to purchasing the Fury or is it because you already owned the 150. I am looking for a cheap bow for playing and was looking at the Man kungs 175lb for the price they seem ok.

Jack Pine
05-29-2012, 09:31 AM
Kamont, welcome to Crossbow Forum. To my knowledge, MK doesn't offer a 175lb crossbow. There is a model #175 with folding limbs that some unscrupulous vendors have been saying is a 175 lb-draw crossbow, but is actually about a 130 lb draw. My friend Ed, one of our sponsors here from www.thecrossbowstore.com can give you more information regarding this, or set me straight if I'm mistaken.
I already owned the MK and liked it, or I would have simply bought another make in the 175 lb draw, but spending the $50 to get the 175 lb prod was the best of both worlds; I got to increase the performance and keep the crossbow I liked the best.

Jack ><>

KSXBOW
11-23-2012, 07:40 PM
Hi Jack
I read about your mods and wondered if you've done those trigger mods yet? I've got an MK and it has a heavy trigger, too. If you have, I'd like some pointers.
Thanks

Joe T.
11-23-2012, 10:27 PM
Research before you buy... Some places are mis-representing the draw weight and/or power stroke. For example, you may see a MK180 XXX listed as a 180lb draw, but it is actually only 130 lbs.... Check the model number you are considering with the manufacturer's website. The Arrow Precision crossbows are manufactured by Poe Lang of Tiawan... One "reputible" store has the Fury II 175 listed with a speed of 305fps and a 16" power stroke. The speed is actually 245, and power stroke is 10". It always pays to double check.

I went a slightly different route with my MK150... I replaced the string with a 25 1/4" Barnett compound crossbow string. So far so good. What used to be my "dead on" sight picture at 20 yards is now dead on at 30 yards. I've only taken 30 shots with it so far, but I plan on doing 50 more tomorrow.

The part number for the Fury II limb is #109. http://shop.arrow-precision.com/p/fury-ii-replacement-limb?s=part_number&part_number_d=ASC&part_number_c=part_number&t=1&i=all&s=part_number&part_number_d=ASC&part_number_c=part_number&t=1&i=all

Joe T.

Jack Pine
11-24-2012, 11:31 AM
Hi Jack
I read about your mods and wondered if you've done those trigger mods yet? I've got an MK and it has a heavy trigger, too. If you have, I'd like some pointers.
Thanks

Howdy KS, welcome to the discussion. No, I haven't done the mods yet; the biggest reason why is, the trigger box, while functional is not all that heavily-built. The side metal is only .060 thick if I remember right [haven't had it apart in a while]. The biggest handicap though, is the fact that the "pins" or "axles" that work as the pivots for the trigger, string claws, and other moving parts, are peened on the ends and do not remove very well without damaging the thin sheet metal sides of the trigger box. I'm just going to live with it until some day when I can get my hands on a milling machine, then design a whole new trigger box. I would really feel better about the whole project if, as I mentioned, the metal was thicker. The very bottom end of the trigger travel is in excess of 1/2". Not a real problem when you get used to it, but very crude by today's standards. If you could dismantle the trigger box without damaging the sides, it looks like it would be fairly simple to improve the function. I get along with it fine, but it sure could be better couldn't it? Well, I didn't pay hundreds of dollars so I guess I won't throw a tantrum about it.
Post some pix of your MK, especially if you've done some mods.

Jack ><>

KSXBOW
11-29-2012, 11:15 AM
The string on my MK 150 is starting to look frazzled on the center serving. I have another string and limb tips to replace it with but I don't know what the bracing should be when re-strung. Got any ideas? Also, should the brace be measured from the inside, outside, or center of the limb?
Thanks.

Jack Pine
11-29-2012, 11:30 AM
The string on my MK 150 is starting to look frazzled on the center serving. I have another string and limb tips to replace it with but I don't know what the bracing should be when re-strung. Got any ideas? Also, should the brace be measured from the inside, outside, or center of the limb?
Thanks.

Howdy KS
The mfr doesn't specify, but I brace mine at 3 1/4" center of prod to center of string and that works very well for me; stresses the prod well and not too hard on it at that distance. Once I set it at 3 1/4", I scribed 2 lines on the side of my rails so I always know where the string should be.

Jack ><>

KSXBOW
11-29-2012, 06:43 PM
Thanks Jack
Mine is braced at about 2.5" which may explain my low bolt speed. That gives me an 11" power stroke, but not nearly as much penetration as I'd like. I don't imagine that I'm close to the 150 lbs I supposed to be pulling, either. I'll brace it up quick.
Thanks again.

Jack Pine
11-30-2012, 08:52 AM
KS, going by memory [which is getting riskier every day] My stroke is 10 1/2" when it's braced at 3 1/4". I just ordered another MK 150, when I get it, I'm going to shoot it through the chrony with the original 150lb prod, then install the 175lb prod. I'll post the results, it will probably arrive midweek next.

Jack ><>

KSXBOW
11-30-2012, 03:13 PM
I impatiently await the results! I spun my string down to about 24 inches to get a 3.25" brace. After shooting it several times, it stretched out to a 3" brace. It also hits pretty well at 50 yards now. Penetration in a hard foam target at 50 is about 10 inches. 40 and under it's closer to 15in. What a difference! Do you use quick spin fletches or standard ones? Did your groups improve when you went to the 14" bolts? Thanks.

KSXBOW

Jack Pine
12-01-2012, 07:28 AM
I impatiently await the results! I spun my string down to about 24 inches to get a 3.25" brace. After shooting it several times, it stretched out to a 3" brace. It also hits pretty well at 50 yards now. Penetration in a hard foam target at 50 is about 10 inches. 40 and under it's closer to 15in. What a difference! Do you use quick spin fletches or standard ones? Did your groups improve when you went to the 14" bolts? Thanks.

KSXBOW

KS, I just use a real low-profile vane [Duravane I think 1.8" long] set on an angle of about 2 degrees. Because the track of my MK is so shallow, this is one of the few vanes that doesn't hit the prod when it flies out, so the arrows don't porpoise when they cross the prod. I have found another way around this, but you'll think I'm crazy, but it works better than I expected; I 2-fletch arrows when I need higher profile vanes for better steerage and don't want them tipping when they launch. I like the stiff vanes the MK arrows are fletched with for this, but I've tried it with others so long as they're 3" long or less. As far as accuracy, I don't notice a whole lot of difference either way, I'm just experimenting a little to improve speed; killed deer with it with a 400+ grain 2219 at slower speeds. I will probably go back to a 2219 at 14" long after this season, only because there aren't any lighted nocks or much of anything available for 2018's. I didn't use to think lighted nocks were all that great, but with my eyesight now, especially in early season when there is no snow, it's great to know where that arrow went with my $10 broadhead LOL!

Jack ><>

KSXBOW
12-10-2012, 10:14 PM
Hey Jack!
Hope you've been busy hunting those monster MI deer. Saw a photo of one last week claimed to be 400 lbs! Had to be a mulie, right?
Still waiting to hear about your 150lb and 175lb speed comparison. Hope you've got the new bow broken in by now.
KSXBOW

Jack Pine
12-11-2012, 11:01 AM
Hey Jack!
Hope you've been busy hunting those monster MI deer. Saw a photo of one last week claimed to be 400 lbs! Had to be a mulie, right?
Still waiting to hear about your 150lb and 175lb speed comparison. Hope you've got the new bow broken in by now.
KSXBOW

Hi KS. No, down in the farm country in the southern half of the state, they grow some real monster whitetails [400 lb would be unusual though], there are no mulies in MI.
Up here in the north country, there is little farm country, the deer basically eat what they can forage in the edgelands along the woods, and don't get very big. Food [and genetics] makes all the difference! When I was a youngster, there used to be scads of deer up here and none downstate, but now that has shifted to the opposite. Partly because of the food situation, but a lot of it is, there are a lot of downstate transplants up here now [they think they're escaping city crime, but bringing it with them], who think it's OK to shoot deer any time they like, and worse, they think doe permits come 20 to a box. Now there are very few deer left in my county and no one has connected the dots between killing breeding does and no deer! DUH!
On the 150-175 thing, the 150 flings a 300 grain arrow at 239.6 fps, and AP Fury prod flings the same arrow at 259. The MK I just got flings it at 256.3. A little string twist will get it right up there.
Jack ><>

KSXBOW
12-12-2012, 10:35 PM
Thanks, Jack. We've got some biggies here in KS but I haven't seen any yet. Got a 150lb buck in October. Only one buck per year, so that has protected several others that size and a little bigger. We're mighty dry down here, so the deer are pretty scarce over about 1/2 mile from water. I'm headed to a state fishing lake that allows hunting tomorrow to see if I can change my luck. Following some of your mods, my bow is now shorter, so are my bolts, and I get some real accuracy since I switched from a 1x red dot to a 4x40 Bushnell. 40 yards is well within my comfort zone now. I'll post some pix/video if I have an luck.

Delta_co
12-23-2012, 06:55 AM
On the 150-175 thing, the 150 flings a 300 grain arrow at 239.6 fps, and AP Fury prod flings the same arrow at 259. The MK I just got flings it at 256.3. A little string twist will get it right up there.
Jack ><>
I just bought the MK150 from TheCrossbowStore. Which speed should I expect out of it stock, 239.6 or 256.3? I plan on doing a similar mod with the limb/prod, but I am considering using a Barnett Veloci Prod. It is 150lb pull, but has a notch formed in it for the vanes to slide through without catching. If it would make a huge difference in speed though, I may go with the same 175lb Fury II limb and use narrower vanes. Let me know.

Jack Pine
12-24-2012, 11:40 AM
I just bought the MK150 from TheCrossbowStore. Which speed should I expect out of it stock, 239.6 or 256.3? I plan on doing a similar mod with the limb/prod, but I am considering using a Barnett Veloci Prod. It is 150lb pull, but has a notch formed in it for the vanes to slide through without catching. If it would make a huge difference in speed though, I may go with the same 175lb Fury II limb and use narrower vanes. Let me know.

Hi Delta, welcome to Crossbow Forum my friend. You should expect about 210 fps out of an MK150 as shipped. This is figuring that you will be using the supplied 2018 14" aluminum arrows weighing about 300 grains. Twisting the string up to give you a 3 1/4" brace height [center of prod to center of string] will increase that to about the 230's or so. The 256 to 260ish or so speeds are figuring using the AP Fury prod. But wait a minute. The last MK I bought had some things that were upgraded on it and it came with a "magnum" [I call it] prod. What I don't know and can't tell you for sure is: "Are they all like that now", or was this just a fortunate accident? The only visible difference in the 175 lb "magnum" prod and the 150 lb prod I got with my 1st MK crossbow is the thickness at the center. My original 150 measured .346 and the AP Fury prods [I have 3] measure in the range of .385, a little more or less, with my last MK measuring .392 or so! No need to spend the bucks for the AP Fury prod if yours is already that thick, the AP Fury prods are not any thicker than that. After you're around MK and similar crossbows, you can tell by looking but you'll want to verify by measuring. The other way to tell is to shoot it through a chronograph, all things being equal, the thicker prod should propel the same arrow faster than the thinner prod.
Now, for the vane clearance issue. I have not tried the Barnett Panzer switch, and I wouldn't mess with it for the following reason. I didn't measure, but visible inspection of a strung Barnett Panzer looked like the brace height was already 5 or 6". If you put that on your MK, you would lose several inches of draw length [power stroke] and would defeat any positive purpose for the switch except for possible vane clearance. I don't know for sure the Panzer prod would even fit, but if it did, I can see where you would be pulling much less than 150 lb.
If you fletch your own arrows, the workaround to the vane clearance problem is [1] use feathers; they're much more forgiving but less durable. [2] Use low profile vanes. I have found the Duravane 1.8" low profile vane to be more than adequate for good steerage and flight with mechanial broadheads, and they only stick up about .380, completely clearing the prod by a good margin [I think in error I posted in another place that the height of that vane was .430; I was in error, that is the height of another low profile vane I have used, the Marko vane, which I don't like as well. Sorry for the mixup, I'm getting older now LOL]. The third workaround I found that works is to 2-fletch with a normal height vane. This is an unconventional fix and looks really weird, but works very well PROVIDED they're not so tall that they dont hit your front sight bracket [if you leave that on and don't use a scope] and less than 3" long. The original arrows that come with the MK use a vane that is very stiff and about 2.6" long and work real well for 2-fletching. I hope this helps you out, and again, welcome; oh, and Merry Christmas to you all.

Jack ><>

Delta_co
12-24-2012, 04:11 PM
Jack

Thanks for the quick reply. The Mk150 came in today and I quickly put it together. I don't have calipers to measure the thickness but it appears to be about 3/8" on a tape measure. This comes out to .375. I know it definitely feels heavier than other 150lb crossbows I've pulled. My brace out of the box is about 3 1/4". After putting a few twists in it, it went up to 3 1/2". I'm not sure how this will affect arrow/bolt speed. Anyone who has an idea let me know. Thanks again for your help. I'll post some pics once I get around to taking them.

Jack Pine
12-25-2012, 10:17 AM
Delta, on that crossbow, the higher the brace the faster the speed with the same arrow. Joe T [my hero] has his braced to an incredible 4 1/2" by using a short string!!! Then if that weren't enough, has it shimmed forward to increase the stroke by 1/4"!! Tells me the MK prods are bulletproof; dry-fired mine several times and they're like the Energizer bunny, they're still going. The only damage was the plastic tips, so you might want to have some on hand if you're as absent-minded as me. Funny thing though, I made strings with 30 strands of BCY 500 and the last dry fire was like it never even happend, the tips didn't even break!! But here's hoping you never have to find out the hard way.

Jack ><>

billygee
12-26-2012, 03:01 PM
Jack

I'm considering trying out that BCY B55 material with around 26 to 28 strands.

Have you or anyone heard of any problems (on Non compound Crossbows)
using B55 because It being a lower stretch from the B50 or B500 material ? :confused:


Billygee

Joe T.
12-26-2012, 06:29 PM
Delta & Jack,

It's funny that the thread is addressing vanes just now. I was too tired to post it last night, but I had a run-in with vanes yesterday. I got a new set of bolts last week. The same brand I've been using, but from a different supplier. I had intended to just set them up with broadheads and use them for hunting next week, since I'm down to 2 undamaged bolts from my last set. But something just kept nagging at the back of my mind... So yesterday afternoon, after all the hub-bub had died down, I took a trip to the range. I started out with an old bolt, and promptly sunk 2 shots into the same hole dead on the "X" at 30 yards... OK, the bow is still in tune.

Unscrewed the practice head and put it on a new bolt. Same range, same rest. 6" low, 3" right! Figured I must have flinched or something, repeated the shot. 4" high, 2" left. And so it went for the next 10 shots, all over the target. Put the head back on the old bolt and slightly enlarged the hole from my first 2 shots. Took 5 more shots with the old bolt, and none missed the mark by 3/4"... Got out another new bolt and was all over the target again!

By this point, I was sure that it was the bolts, so I started examining the 2 I used closeley.
A. Gouges in the nocks. The nocks are about .006 bigger in diameter than the shafts! They're catching in the joint between the rails and nosepiece!
B. Vanes are positioned 5/8" rearward of where they should be! They're actually going back into the action far enough to "fold".
C. For the first time EVER, I found wear on the edge of the cock vane. I haven't decided yet whether it's hitting the prod hard enough to chew it up, or if something in the action is chewing it.

Keep in mind that I'm comparing it to the same brand of bolt with the same size vanes, which have been shot over a hundred times each... The old bolts have none of these marks... So I know I'll have to re-fletch and fix the nocks before I can use them. Out comes the fletching jig, and I go digging through my supply of vanes... Got enough 2" Blazers to do the job, but a quick check reveals that they're deep enough to thit the prod...

I put in a bid for some 4" "low profile" Flex-Fletch vanes. (.360" height, 7 gr. each) If I win the auction, I'll report on how they work out.

One bright spot, though... A c0-worker approached me today and asked me to "PLEASE come over to my place and kill some deer!" They're eating his expensive flowers and shrubbery, and driving his "little yappy" mutt crazy. Deer have been a little scarce on public grounds since gun season 3 weeks ago, and it's nice to be invited to hunt on private land...

Joe T.

Jack Pine
12-27-2012, 04:03 PM
Jack

I'm considering trying out that BCY B55 material with around 26 to 28 strands.

Have you or anyone heard of any problems (on Non compound Crossbows)
using B55 because It being a lower stretch from the B50 or B500 material ? :confused:


Billygee

BG, I haven't tried B55, but B500 has a lot of stretch, so much so in fact, that you have to take the stretch out OR it will take around 50 shots to do it. I actually use a come along between 2 trees to take it out. I would think that a lower stretch material would be good, but since I've got a couple of B500 around, I'm not about to switch any time soon. I think I mentioned before that I dry-fired with a B500 30-strander and it was like it never even happened; didn't even break the removable prod tips!! A lower stretch might not be that forgiving.

Jack ><>

Jack Pine
12-27-2012, 04:10 PM
Joe, you'll see a diff with the lo-pro vanes, 4" might be extreme though, I put mine on an angle instead of straight down the shaft and 3" is about the max that works well for me, maybe you'll have better luck.

Jack ><>

billygee
12-27-2012, 08:20 PM
BG, I haven't tried B55, but B500 has a lot of stretch, so much so in fact, that you have to take the stretch out OR it will take around 50 shots to do it. I actually use a come along between 2 trees to take it out. I would think that a lower stretch material would be good, but since I've got a couple of B500 around, I'm not about to switch any time soon. I think I mentioned before that I dry-fired with a B500 30-strander and it was like it never even happened; didn't even break the removable prod tips!! A lower stretch might not be that forgiving.

Jack ><>

Jack

I have quite a bit left of Brownell B50 Dacron myself that I have used on older vertical bows
and my MKs. (26-strands.)
Haven't had quite that bit of Sssssstretch :rolleyes: but just read the B55 was the upgrade to the B500
and just got my curiosity going.
Haven't had any dry fires yet, hope not to, but never can tell.

On the other side of the string, been using the ZEON FUSION by Norway 2.1
Really stand out with their Ultra Bright Glow. been shooting them out of my Mod MK 150 – A1BC (Wooden Stock)
Haven't had any damage showing up yet,
except the glue must have been bad and didn't hold some on.
changed to a quick bond adhesive.
Also should there be clearance contact issue with my MK-150A3AC these Vanes have
straight line Ribbed Vanes that one can use for trimming.

billygee

Delta_co
12-27-2012, 08:31 PM
Has anyone done the AR15 trapdoor buttplate mod yet? I am in the middle of it and was wondering if anyone had any suggestions? So far it's pretty straight forward. Shave with a Dremel, Line it up, Screw it on, and shave to final fit.

Jack Pine
12-28-2012, 11:44 AM
Has anyone done the AR15 trapdoor buttplate mod yet? I am in the middle of it and was wondering if anyone had any suggestions? So far it's pretty straight forward. Shave with a Dremel, Line it up, Screw it on, and shave to final fit.

Delta, I've been thinking about this for some time now and would be interested in your mod and pix and info on where you got it, cost etc.
Jack ><>

Jack Pine
12-28-2012, 11:49 AM
Jack

...Haven't had any dry fires yet, hope not to, but never can tell...
billygee

LOL BG. One day Mrs. Pine looked out the door and came excitedly into where I was watching the telly and said "There's a bunch of turkeys outside". I had a permit, so I ran to get the Mighty MK, grabbed an arrow, held it in my mouth while I cocked it, carefully opened the door, aimed and fired. Then there was that awful noise of a dry fire! In my excitement, I forgot to take the arrow out of my mouth and load it. DUH!! She's real reluctant to leave me unsupervised anymore; I just don't understand it.

Jack ><>

billygee
12-28-2012, 02:12 PM
LOL BG. One day Mrs. Pine looked out the door and came excitedly into where I was watching the telly and said "There's a bunch of turkeys outside". I had a permit, so I ran to get the Mighty MK, grabbed an arrow, held it in my mouth while I cocked it, carefully opened the door, aimed and fired. Then there was that awful noise of a dry fire! In my excitement, I forgot to take the arrow out of my mouth and load it. DUH!! She's real reluctant to leave me unsupervised anymore; I just don't understand it.

Jack ><>

Jack

One could say I may have had a somewhat Dry Fire on my Eagle. :confused:
Had a shot at a nice Buck from my tree stand, only to have the Bolt
deflect off a hidden branch I forgot to remove.
So I re-cocked my Eagle from 20ft up sitting on a heavy Branch (somewhat awkward)
Then, Yep you guessed it, Here comes one from behind me, waited for a Good Broadside Shot
and took it with the White Tail waving Bye! Bye!
Huh, I thought, It Didn't even know it was Hit. As I relived the shot, strange, but I never heard the hit, which was only 15yds. As I looked at my Crossbow, there the bolt was, out about 1/4 the way, and the string having a mess of broken strands.
Near as I can tell to this day is, I must have had only one side of the string cocked in the sear. :(
No Damage to the Eagle that a new string couldn't fix.

One of those stories of the one that got away. :o

billygee

Delta_co
12-28-2012, 03:12 PM
I'll post pix when I finish it up. I got an A1 style buttplate with trapdoor from eBay for $6 shipped. It didn't include screws but the original MK screws will work. To get it to fit on the "sniper" model from the crossbowstore, I simply removed the trapdoor assembly and took a dremel to the back of the buttplate. I removed any material that would sit inside the stock of the AR15. Essentially, I made it flat just like the original MK buttplate. As for mounting holes, I simply positioned the plate and drilled new holes for the original screws in the stock. The AR buttplate holes are about 3/8" higher and lower than the original holes. Once drilled, I installed the screws and secured the buttplate. The AR buttplate is a little wider at the top and bottom than the original plate. Now that I have it mounted. I'm going to mask the stock and sand the buttplate to match the contour. I should have it finished in the next few days. You could stop and not do the contour match as its only off maybe 1/16-1/8". I'll post pics shortly of where I am at.

Edit for pics:

http://i1150.photobucket.com/albums/o604/Tango_Co/40B25296-1ED5-4684-B754-AC681144E768-4468-000001F488779BAC_zps3b723c3f.jpg

http://i1150.photobucket.com/albums/o604/Tango_Co/F23E8822-EF53-4E17-AFCE-A3350B6DAA5B-5251-000002563765CF13_zpsb7f03109.jpg

You can see the overhang in pic 2. I'm working on sanding that section now.

Delta_co
12-28-2012, 06:22 PM
Jack

Other than the tips, does a dry fire damage the limb on the MK or is it a string/tip issue only?

jder30
12-28-2012, 06:32 PM
sweeeeet!
Will the cocking rope fit through the trap door for storage?

jder30
12-28-2012, 06:34 PM
I accidentally dry fired and damaged my tips . Nothing else was damage.

JD

Delta_co
12-28-2012, 06:44 PM
I don't know, I haven't gotten a cocking rope yet. If you measure the handles, I'll let you know if they fit.

jder30
12-28-2012, 07:00 PM
I am just about done with most of my mods

I added some felt on my limbs to reduce the string snap
I just finished making another set of arrows:
16" Gold Tip XT Hunters 7595 (.340 Spine) .125gr tips, 10.2 GPI = Total AVG WT 312GR
The outer diameter on these are .310 which fits perfect! Plenty of room for the string to catch!

So far I have did the following mods:

1. Added a custom ViperTrail crossbow string w/bats string silencers
2. Added TruGlo Red Dot scope
3. Removed Front and rear open Sights
4. Added Apex Gear Quiver
5.Added sling
6. Added limb felt between the limb and prod ends (Kinda works!)
7. Polished trigger sear contact points to reduce creep and smooth out trigger pull
8. Mini Limb savers on prod
9. 16" .300 and7595 Custom Gold Tip crossbow arrows

I odered some B50 dacron to make my own flemish string; however, I am very impressed with Vaper Trail continuous loop custom crossbow string.
I may also order the trapdoor butt plate.

I am really enjoying my crossbow! The trigger job and new arrows make me enjoy it even more.

My crossbow w/ New Gold Tip 16" 7595 arrows
http://i45.photobucket.com/albums/f73/jder30/87DDFCDD-1045-4B31-91CE-3D193D52A179-460-00000024319D2490.jpg

Limbs showing felt material:
http://i45.photobucket.com/albums/f73/jder30/1B061FFC-6786-4ADC-9381-3461F7CA49AC-460-00000024248CE9BB.jpg

JD

Delta_co
12-28-2012, 07:30 PM
JD

How did you mount the weaver rail for your red dot? Did it line up with existing holes, or did you need to drill?

Joe T.
12-28-2012, 08:02 PM
Has anyone done the AR15 trapdoor buttplate mod yet? I am in the middle of it and was wondering if anyone had any suggestions? So far it's pretty straight forward. Shave with a Dremel, Line it up, Screw it on, and shave to final fit.

I haven't done this mod, but in my younger days I did quite a bit of custom gunstocking, and here's how I handled Buttplates, spacers, trimplates, etc.

First, remove an existing Buttplate or trim. Then, run a strip of masking tape around the stock at the joint. It needs to be smooth and should extend to the very end of the stock. If a little hangs over the edge, it can be trimmed flush with a razor blade. Next, tape up the "stock" side of the plate, completely covering it and temporarily mount the raw buttplate. Using a shap-pointed awl (icepick?) or X-acto knife, trace the outline of the stock into the buttplate, cutting through the tape and leaving a fine line in the plate. Peel the scrap tape off the buttplate before un-mounting it.
Now you should have the perfect outline of the stock etched into the buttplate, and the tape that was under the plate makes the outline very easy to see. What you do next depends on how you intend to remove the excess material. For hand-cutting with a coping saw, or using a hand-held jigsaw, Mount the plate "backwards" to a scrap of wood, so you can mount it in a vise and be able to see what you're doing. For a "table type" jigsaw or bandsaw, mount it to a wood scrap on the taped side, to make a handle to guide it through the saw without risking your fingers. Cut right up to but NOT into the tape.
Final shaping is done with a file, followed by progressively finer sandpaper for smoothing. Remove all tape, and it should fit perfectly with no scratches on stock or plate.

Joe T.

jder30
12-28-2012, 08:14 PM
The new Mk 150A3B are now being shipped with weavers and stiffer Prods! (175LB!)

jder30
12-28-2012, 08:22 PM
I'll post pix when I finish it up. I got an A1 style buttplate with trapdoor from eBay for $6 shipped. It didn't include screws but the original MK screws will work. To get it to fit on the "sniper" model from the crossbowstore, I simply removed the trapdoor assembly and took a dremel to the back of the buttplate. I removed any material that would sit inside the stock of the AR15. Essentially, I made it flat just like the original MK buttplate. As for mounting holes, I simply positioned the plate and drilled new holes for the original screws in the stock. The AR buttplate holes are about 3/8" higher and lower than the original holes. Once drilled, I installed the screws and secured the buttplate. The AR buttplate is a little wider at the top and bottom than the original plate. Now that I have it mounted. I'm going to mask the stock and sand the buttplate to match the contour. I should have it finished in the next few days. You could stop and not do the contour match as its only off maybe 1/16-1/8". I'll post pics shortly of where I am at.

Edit for pics:

http://i1150.photobucket.com/albums/o604/Tango_Co/40B25296-1ED5-4684-B754-AC681144E768-4468-000001F488779BAC_zps3b723c3f.jpg

http://i1150.photobucket.com/albums/o604/Tango_Co/F23E8822-EF53-4E17-AFCE-A3350B6DAA5B-5251-000002563765CF13_zpsb7f03109.jpg

You can see the overhang in pic 2. I'm working on sanding that section now.

I just ordered one from ebay as well. The one I ordered is a new USGI Colt AR A2. Mine was costly. It Cost me $21 to my door.

http://i45.photobucket.com/albums/f73/jder30/coltA2TRAPDOOR_zpsf561d589.jpg

Delta_co
12-28-2012, 08:40 PM
JD

Not a bad price at $21. I was looking at that one and almost bought it. I like the A2 style more than the A1. But at $6 shipped I couldn't pass up the deal.

jder30
12-28-2012, 09:02 PM
Delta & Jack,

It's funny that the thread is addressing vanes just now. I was too tired to post it last night, but I had a run-in with vanes yesterday. I got a new set of bolts last week. The same brand I've been using, but from a different supplier.

I put in a bid for some 4" "low profile" Flex-Fletch vanes. (.360" height, 7 gr. each) If I win the auction, I'll report on how they work out.

One bright spot, though... A c0-worker approached me today and asked me to "PLEASE come over to my place and kill some deer!" They're eating his expensive flowers and shrubbery, and driving his "little yappy" mutt crazy. Deer have been a little scarce on public grounds since gun season 3 weeks ago, and it's nice to be invited to hunt on private land...

Joe T.

Just installed some 3" 3D DURAVANES these are low-profile vanes .436 high. clears the barrel channel nicely on my MK150.
However, the groupings are tight and fly the same as the 2' twister vanes on my other arrows.

jder30
12-29-2012, 10:03 AM
Replace that factory string!! My friend just got his MK150 A3B and the serving started separating and began to fray after 15-20 shots.
He applied server string wax, lubed the rails, etc. prior to shooting. That still wasn't enough! The string, to me is the weakest part of this whole set up!
His crossbow is a lot louder, shoots slower and vibrates more than my modified bow. My custom VaperTrail string and dampening material made a very noticeable difference in comparison. However, his did ship with the thicker prod and metal weaver scope rail. He ordered a custom string from VaperTrail as well. Oh, by the way, good luck finding someone to make a custom Flemish string for these lil MK150s. Most will only make a Flemish string for the big name brands of crossbow. Hopefully, when I receive my string material I will be able make my own flemish string.

JD

Jack Pine
12-29-2012, 05:11 PM
Jack

Other than the tips, does a dry fire damage the limb on the MK or is it a string/tip issue only?

Delta, I can't speak to every situation and every shooter, but I probably have about 4 dry fires to my discredit, and so far it's only affected the tips. I replaced my string with one I made from 30 strands of B500, and it didn't even affect the tips; I think because the B500 is more forgiving, or maybe it was just dumb luck.
Jack ><>

jder30
12-30-2012, 08:39 AM
Replace that factory string!! My friend just got his MK150 A3B and the serving started separating and began to fray after 15-20 shots.
He applied server string wax, lubed the rails, etc. prior to shooting. That still wasn't enough! The string, to me is the weakest part of this whole set up!
His crossbow is a lot louder, shoots slower and vibrates more than my modified bow. My custom VaperTrail string and dampening material made a very noticeable difference in comparison. However, his did ship with the thicker prod and metal weaver scope rail. He ordered a custom string from VaperTrail as well. Oh, by the way, good luck finding someone to make a custom Flemish string for these lil MK150s. Most will only make a Flemish string for the big name brands of crossbow. Hopefully, when I receive my string material I will be able make my own flemish string.

JD

Just received two spare custom crossbow strings from Stone mountain Bow strings. These were $14 each (cheaper than VaperTrail $45 for one!) and made very nice! The serving around the loop ends and center serving was done perfect and tight! I will store theses inside a Ziploc bag inside my stock when I get my trapdoor butt-plate ;)

http://i45.photobucket.com/albums/f73/jder30/C3373D0E-860E-41E1-B7FC-2446CFA9395D-120-00000003E676897D.jpg

Jack Pine
12-31-2012, 08:39 AM
Wow JD, $14 isn't much more than the cheap Asian strings, and if they're wound tighter, should keep from separating. How many strands? You ought to tuck a couple of prod tips in there with 'em just in case.

Jack ><>

Joe T.
12-31-2012, 10:40 AM
I find I can get a factory string, "my" string, stringer and 2 tips in there. It's a squeeze, though, and no bag. (Also no trapdoor...) If the string breaks outright, I'll need the stringer to put the factory string on, and I have to have it cocked with the factory string in order to put the string I use on it... It gets complicated sometimes, LOL. Anyway, it forced me to leave out the sights and wax. But it packs tight and doesn't rattle. If I break the scope, I'll have to walk back to the car... I guess my old scope will have to go into my possibles bag... It's set to shoot 2" high at 25. Still better than iron sights.

Joe T.

eem242
01-03-2013, 05:01 PM
I was reading through this thread and I was hoping you guys could help me out. I recently got one of the MK 150# crossbows. I was hoping to use a cocking string with it, but I don't think this is possible since there is nowhere on the stock to hold the string. I was hoping to find some suggestions on what to do here. I may just be missing something. Is there any way at all to use some kind of cocking device? Thanks!

Joe T.
01-03-2013, 06:56 PM
I was reading through this thread and I was hoping you guys could help me out. I recently got one of the MK 150# crossbows. I was hoping to use a cocking string with it, but I don't think this is possible since there is nowhere on the stock to hold the string. I was hoping to find some suggestions on what to do here. I may just be missing something. Is there any way at all to use some kind of cocking device? Thanks!

Welcome to the thread eem242!

I have no trouble using the MK cocking rope.
http://i1293.photobucket.com/albums/b583/Joe_T1/Rollerpassingsafety_zps29b9acf3.jpg[/IMG]

This is how I run it accross the back.

Joe T.

Delta_co
01-04-2013, 07:34 AM
I just finished the trap door buttplate and got in the mood to change the color. I also removed the metal stirrup and replaced it with 1 inch nylon webbing. It's a lot quieter now since the metal isn't banging around.

http://i1150.photobucket.com/albums/o604/Tango_Co/49391F6A-FF59-4AC2-A2F0-9F79965D337D-12551-000005CE0CDA68EB_zps1eef795a.jpg

billygee
01-04-2013, 11:30 AM
Joe

Nice looking camo, is that factory ? :confused:

billygee

Jack Pine
01-04-2013, 11:33 AM
I just finished the trap door buttplate and got in the mood to change the color. I also removed the metal stirrup and replaced it with 1 inch nylon webbing. It's a lot quieter now since the metal isn't banging around.

http://i1150.photobucket.com/albums/o604/Tango_Co/49391F6A-FF59-4AC2-A2F0-9F79965D337D-12551-000005CE0CDA68EB_zps1eef795a.jpg

LOL Delta, don't let the military see you with that color or they'll ship your butt to the desert to hunt camels with it!! Nicely done, I really like your strap/stirrup. How about a tutorial on how you adapted/installed the trapdoor? I took a few brief glances at mine and haven't decided on the best way to procede yet.

Jack ><>

jder30
01-04-2013, 12:21 PM
Super nice!!

JD

Delta_co
01-04-2013, 12:25 PM
Thanks for the positive feedback on the paint job. If anyone wants a similar look, I used Krylon Camo Khaki. Here is the link to the Trapdoor DIY.

http://www.crossbowforum.com/showthread.php?4140-Man-Kung-AR-Trap-Door-Buttplate-DIY&p=13740#post13740

sharky
01-04-2013, 03:19 PM
Hi, ive just bought the MK 150lb but with a diff name (Buffalow ridge) and i shot it thru my chrony and i got 101fps and 134fps so i doubted the poundage on it i spoke to a guy that put it on a tiller and it came up as a 100lb draw!! When i spoke to MK they said the MK150 and the MK180 are both 130lb..anyway ive replaced the two limbs with a single jag 175lb and got 287fps and 291fps could you please tell me if its safe loading it with a 175lb prod as im a bit concerned about the trigger holding that much back.

Jack ><>[/QUOTE]

Delta_co
01-04-2013, 04:44 PM
Hi, ive just bought the MK 150lb but with a diff name (Buffalow ridge) and i shot it thru my chrony and i got 101fps and 134fps so i doubted the poundage on it i spoke to a guy that put it on a tiller and it came up as a 100lb draw!! When i spoke to MK they said the MK150 and the MK180 are both 130lb..anyway ive replaced the two limbs with a single jag 175lb and got 287fps and 291fps could you please tell me if its safe loading it with a 175lb prod as im a bit concerned about the trigger holding that much back.

Jack ><>[/QUOTE]

Jack

You should be fine with the 175lb prod. I'm not positive, but I believe most MK models use the same trigger assembly with one exception that I know of. If you don't feel comfortable with it, I'll trade you my 150lb prod for your 175lb.

Delta_co
01-06-2013, 09:33 PM
Just got a Grayling Jus N uff quiver. Amazingly, the screws for the mount plate are the correct size for the mount holes in the MK. I definitely recommend this one. It can be had for under $10 from ShootingTheX.com.

jder30
01-07-2013, 08:09 PM
Hey ordered an Excalibur quiver bracket. I drilled and tapped some screw holes on the side of my MK150A3B crossbow
and added my Apex Gear Nano quiver. Turned out nice! I originally had the quiver mounted towards the front, under the rail of my crossbow,
but the quiver would turn since it was held on using one screw.

http://i45.photobucket.com/albums/f73/jder30/C7BA7E5C-5941-43E1-B659-D0A931AE376D-421-0000002055AAAA1B.jpg

Another view:
http://i45.photobucket.com/albums/f73/jder30/BEAC2D34-6C34-4DB8-8E5F-5E2791FA07FC-421-000000387C5C5745.jpg

Delta_co
01-07-2013, 08:49 PM
Hey ordered an Excalibur quiver bracket. I drilled and tapped some screw holes on the side of my MK150A3B crossbow
and added my Apex Gear Nano quiver. Turned out nice! I originally had the quiver mounted towards the front, under the rail of my crossbow,
but the quiver would turn since it was held on using one screw.

http://i45.photobucket.com/albums/f73/jder30/C7BA7E5C-5941-43E1-B659-D0A931AE376D-421-0000002055AAAA1B.jpg

Looks great, I have been contemplating getting this bracket.

jder30
01-07-2013, 09:34 PM
Yeah, I think the lil Apex quiver compliments this compact size crossbow.

Jack Pine
01-08-2013, 11:26 AM
Hey ordered an Excalibur quiver bracket. I drilled and tapped some screw holes on the side of my MK150A3B crossbow
and added my Apex Gear Nano quiver. Turned out nice! I originally had the quiver mounted towards the front, under the rail of my crossbow,
but the quiver would turn since it was held on using one screw.

http://i45.photobucket.com/albums/f73/jder30/C7BA7E5C-5941-43E1-B659-D0A931AE376D-421-0000002055AAAA1B.jpg

Another view:
http://i45.photobucket.com/albums/f73/jder30/BEAC2D34-6C34-4DB8-8E5F-5E2791FA07FC-421-000000387C5C5745.jpg

Nice looking rig JD!!

Jack ><>

KSXBOW
02-10-2013, 08:01 PM
I made my cocking rope out of a longer rope, 2 S-hooks and a couple of pieces of aluminum tube I had lying around. Cheap and it works. I really like the one inch bootstrap. I think that will go on mine in the summer mod season.

KSXBOW
02-10-2013, 08:46 PM
Just received two spare custom crossbow strings from Stone mountain Bow strings. These were $14 each (cheaper than VaperTrail $45 for one!) and made very nice! The serving around the loop ends and center serving was done perfect and tight! I will store theses inside a Ziploc bag inside my stock when I get my trapdoor butt-plate ;)

http://i45.photobucket.com/albums/f73/jder30/C3373D0E-860E-41E1-B7FC-2446CFA9395D-120-00000003E676897D.jpg

What were the specs you sent them? That looks really nice. I just checked out their site and really want to know what you asked for so I can get me a couple. My factory string finally went kaput after lots of shooting this season.

jder30
02-10-2013, 09:16 PM
What were the specs you sent them? That looks really nice. I just checked out their site and really want to know what you asked for so I can get me a couple. My factory string finally went kaput after lots of shooting this season.

Ordered 26.75 crossbow string, 28 strands, w/ 3/4" loop ends

CaptAmerica
02-22-2014, 12:08 PM
Thanks Jack, very interesting, I kook forward to reading more.