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View Full Version : Monopod mod for Magpul STR



Warg
05-17-12, 15:50
I recall reading a thread where Trident had modified at UBR to accept a picatinny rail and monopod. I wanted to do something similar with one of my collapsible stocks, so I purchased a LaRue POD for the CTR. While this worked okay, I wasn't necessarily a fan of the CTR's cheek weld, even with LaRue's RISR, so I sought another solution. I thought about grinding and reshaping the bottom of several stocks to fit the POD. This would be easy to acheive with the SOPMOD and STR and could likely work for the IMOD/EMOD. However some compromises would have to be made, e.g., obstructing the QD mounts in the case of the SOPMOD.

Looking at the STR, I noticed a removable plug on the bottom of the stock (buttpad removed). Perhaps Magpul created this for a future add-on product?:

http://i304.photobucket.com/albums/nn176/Dr_Wolfenstein/ARs/DSCN2186_sm.jpg

Once removed, I started thinking it would be easy to mount a small picatinny rail in this slot (Note that I filed a tiny bit of the bottom of the STR to flatten/remove the radius):

http://i304.photobucket.com/albums/nn176/Dr_Wolfenstein/ARs/DSCN2188_sm.jpg

Thus, I started examining and hacking away at some spare rails. I found a couple of small composite rails that looked like they would work, but they seemed too fragile once screwed in place. The ideal piece for my monopod, the Accu-Shot BT12-QK, was this little guy, the aluminum MI MCTAR-05:
http://www.jsesurplus.com/images/products/thumb/mctar05.1.jpg

The rail was a bit too long, but was the correct width to fit into the STR. Using a cutoff wheel on a handheld grinder, I shortened the rail by removing the longer portion of the rail near the second fastener hole. I also found a suitable backing plate that came from Magpul's MOE accessory rails.

http://i304.photobucket.com/albums/nn176/Dr_Wolfenstein/ARs/DSCN2187_sm.jpg

Once cut, the rail fit into the STR in a very secure manner. I've angled the backing plate to ensure more area comes into contact with internal ribbing in the stock. I may fabricate a larger backing plate if necessary, but it appears to be very secure as is:
http://i304.photobucket.com/albums/nn176/Dr_Wolfenstein/ARs/DSCN2190_sm.jpg

The finished product:
http://i304.photobucket.com/albums/nn176/Dr_Wolfenstein/ARs/DSCN2182_sm.jpg

http://i304.photobucket.com/albums/nn176/Dr_Wolfenstein/ARs/DSCN2193_sm.jpg

I still have to test this modification, but it seems very stout and secure.

fallenromeo
05-17-12, 17:10
nice work. Interested to see how it holds up when you test it.

RD62
05-17-12, 17:35
Very interesting.

Looking forward to the results of your testing.

VooDoo6Actual
05-17-12, 18:55
nice Mod.

well done.

ALCOAR
05-17-12, 19:11
Hell yeah......fantastic job!

Also what a really nice surprise to hear you mention the only thing that I hoped to accomplish with that previous DIY mod thread....give folks some simple food for thought in order to get their creative processes flowing towards DIY'ing solutions for their particular needs or uses.

Look forward to hearing how you like it once you use it:)

http://i888.photobucket.com/albums/ac81/trident1982/DSC04065-1.jpg

Warg
05-19-12, 13:33
Thanks guys. I leaned a 100 lb plate on the rear of the buttstock with the monopod deployed and left it there for a couple of days with no apparent effect. If I did my physics calcs correctly, the little monopod and mount were supporting a 57 lb static load.

Headed to San Diego for a few days. Will resume testing at the range when I return.

Warg
06-28-12, 11:50
I've pretty much run this setup through the ringer on two different ARs prone and on the bench. The newest is pictured below:

http://i304.photobucket.com/albums/nn176/Dr_Wolfenstein/ARs/DSCN2307_sm.jpg
Showing monopod mount.


http://i304.photobucket.com/albums/nn176/Dr_Wolfenstein/ARs/DSCN2313_sm.jpg
With bipod.

http://i304.photobucket.com/albums/nn176/Dr_Wolfenstein/ARs/DSCN2318_sm.jpg
Bipod and monopod collapsed.

The setup is solid, however, for me the monopod is a tad higher than it needs to be when locked vertically and set on the shortest elevation for shotting on a flat range or uphill. To even things out, I have to extend the bipod a notch or two and then I notice that my neck starts to bother me which hasn't been an issue using a rear bag. Downhill is not an issue, obviously.
http://i304.photobucket.com/albums/nn176/Dr_Wolfenstein/ARs/DSCN2321_sm.jpg
Bipod extended two notches.

In retrospect, perhaps I should have opted for the shorter BT12 with this stock.
http://www.accu-shot.com/catalog/images/sm_BT12.jpg

I don't typically use monopods and currently still prefer a rear bag given the generous amount of flexibility a bag affords- particulrly when shooting muliple platforms per outing. On the bench the monopod works well, but again maybe a tad to high for me. I was pleased to find that you can use this monopod in a similar manner as a rear bag by varying the angle (and height) in your hand. That is, using it as a lever when not fully locked vertically. This method seems to be very repeatable and precise and is particularly beneficial when prone. In this manner, I'm pleased with the choice of the BT12-QK.

CodeRed30
07-13-12, 22:05
Barrel specs please :)

Warg
07-13-12, 22:12
Barrel specs please :)

It's a Kreiger 1:7 twist SS SPR profile barrel with Compass Lake chambering and rifle length gas. I did the graphite black Cerakote and am using a Noveske thread protector which I think is made by AAC.

CodeRed30
07-14-12, 00:56
Kreiger makes some SOLID stuff! I'm super jealous. What's the Compass Lake chambering?

Warg
07-14-12, 17:09
CLE's chamber is a proprietary match spec that is very similar to Wylde with a bit longer throat for 80 gr bullets.