Magpul PRS: AR15 vs AR10

[InTheWeeds]

After having cycling issues with my DPMS LR-6.5, A fellow shooter at the range asked me if I had installed the AR-10 version of the Magpul PRS. I honestly had no idea there was a difference, but he said if you look at them side by side, I would see the difference in the length of the cheek piece. I was wondering if anyone had some pictures of both to compare. I also put a new fore end on my rifle, so I dont know yet if it was an issue with the gas block leaking/being installed improperly..

 

[Scottmilk9]

Re: Magpul PRS: AR15 vs AR10

I have no pictures, but the only thing that would go wrong changing a buttstock out is if you put in a carbine buffer, PRS stocks require a rifle length buffer.

I'd check your gas system first.

 

[bassfishindoc]

Re: Magpul PRS: AR15 vs AR10

You can find pictures of the differences on google. The only difference is the cheek piece on the AR10 version is shorter to accommodate the longer pull of the charging handle. Other than that they are identical and the AR-10 version can be used on the AR-15 without worry. It shouldn't be the PRS that is causing the cycling issues unless you somehow managed to bend the buffer tube and that is binding up the bolt carrier, although if you did that I don't think you would be able to fit a PRS over a bent buffer tube.

 

[InTheWeeds]

Re: Magpul PRS: AR15 vs AR10

Yea, I just found my answer, dont know why I didnt think of it before. I didnt change the buffer tube, so therefore the bolt is still cycling the same length as before. Its gotta be in the gas system..
Any ideas where to start there? Did I ruin a seal on the gas block?

 

[Redmanss]

Re: Magpul PRS: AR15 vs AR10

Did you use the plate screw provided with the PRS, or did you use one for a standard fixed stock? There's a small but significant length difference that can cause malfunctions. The standard one is just a tiny bit too long....

 

[Badshot308]

Re: Magpul PRS: AR15 vs AR10

Along those lines, check out this thread http://www.snipershide.com/forum/ubbthre...997#Post2532997 It seems some people were having trouble with the supplied PRS screw being a little bit too long and causing malufunctions.

 

[steelcomp]

Re: Magpul PRS: AR15 vs AR10

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Badshot308</div><div class="ubbcode-body">Along those lines, check out this thread http://www.snipershide.com/forum/ubbthre...997#Post2532997 It seems some people were having trouble with the supplied PRS screw being a little bit too long and causing malufunctions. </div></div>X3

 

[Redmanss]

Re: Magpul PRS: AR15 vs AR10

Ahh, didn't know there was also issues with some of the supplied screws. Noted.

 

[AXEMAN]

Re: Magpul PRS: AR15 vs AR10

also, the screw for the PRS is vented so that air can escape the tube as the buffer travels thru the tube. if you dont have the right vented screw, there will be too much air pressure in the tube. think plunger in a syringe

 

[Scottmilk9]

Re: Magpul PRS: AR15 vs AR10

check the alignment of the gas block, thats probably where the issue lies. Make sure its lined up with the gas port, take it to the range and whatever tools you need. Put one round in the mag and fire it to see if it locks back and go from there.

Don't discount what others say either, its quite possible that other things can be wrong, but check gas first.

 

[SmokyJoe]

Re: Magpul PRS: AR15 vs AR10

When I put a PRS stock on my P308, I used Hellbender's write-up on adjusting bolt overrun to fine tune the amount of space between the bolt and the bolt catch. Very clear instructions on how to see if there is enough or too much clearance for the bolt. Not enough clearance and you may have feed issues. Too much clearance and the bolt catch gets hit harder than necessary.

Hellbender's How To on bolt catch overrun is here:
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1986200

In my case, the Magpul screw was too long so I had to grind it down so the plastic tip on the buffer wouldn't get impaled on it. After grinding down the screw, I added two 'vented' quarters to get the clearance right.

On a side note, the screw that Magpul sent me was not vented. There was a hole drilled about half way through their screw. I called Magpul to find out if it had to be vented and was told that the vent is to let water out in the event the stock is inundated, and that it had been requested for military contracts. He went on to say that there is enough clearance around the chamfered edges of the buffer to let air out, so air pressure would not be an issue. When I fired the rifle this week, everything worked fine.

 

[SD26]

Re: Magpul PRS: AR15 vs AR10

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: D.Draig</div><div class="ubbcode-body">When I put a PRS stock on my P308, I used Hellbender's write-up on adjusting bolt overrun to fine tune the amount of space between the bolt and the bolt catch. Very clear instructions on how to see if there is enough or too much clearance for the bolt. Not enough clearance and you may have feed issues. Too much clearance and the bolt catch gets hit harder than necessary.

Hellbender's How To on bolt catch overrun is here:
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1986200

In my case, the Magpul screw was too long so I had to grind it down so the plastic tip on the buffer wouldn't get impaled on it. After grinding down the screw, I added two 'vented' quarters to get the clearance right.

On a side note, the screw that Magpul sent me was not vented. There was a hole drilled about half way through their screw. I called Magpul to find out if it had to be vented and was told that the vent is to let water out in the event the stock is inundated, and that it had been requested for military contracts. He went on to say that there is enough clearance around the chamfered edges of the buffer to let air out, so air pressure would not be an issue. When I fired the rifle this week, everything worked fine. </div></div>
Great post! Tons of help! Thanks!