Gas Gun for PRS

D

DocRDS

Head Maffs Monkey
Full Member
Minuteman
Feb 21, 2012
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The Great Beyond
#1
Thinking about running a gas gun in PRS because why not (I need to keep myself entertained).

I have an older DPMS (Gen 1) 308 that runs. As with all things, AR related, the obvious solution is get a 22" 6.5 creedmoor upper. (I shoot a lot of 6.5 manbun already)
Problem--none of the uppers are compatible with each other, and finding the right DPMS upper could be a problem. That's option 1:

Option 2 is rebarrel. I've done light work on my bolt guns, but AR is more intimidating. TBH I just wanna fn shoot and not mess with the crap.

Option 3 is buy--probably a seekins or maybe a JP/GAP. Lets be honest--I'm not in the running for any wins or class leads, so anything over a seekins price is wasted money.

My goal is to have a running setup that I don't have to F with, just clean it, reload shoot, repeat. Advice on how to proceed would be appreciated. For a barrel like I mentioned 22" heavy barrel, and I do like the seekins handguard for barricades and whatnot. ANy other things to watch for for quality of life? AGB worth it? I generally run a brake in comp, but I do have a can and I know the ARs get fussy.
+2 length system?
Triggers -n- crap I've been doing forever.
Not a super fan of side chargers simply because I've used the "standard" AR-15 style. I can learn (I had to reteach myself to shoot left handed).

Input and cheap shots are welcome
 
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#2
What model 308, specifically? If it’s the 24” bull barrel lr-308, run that. Mine is precise enough for a hobbiest shooter not hunting PRS match wins. Otherwise, rebarreling a lr-308 is arguably easier than rebarreling a bolt gun.
 
#3
DocRDS said:
Thinking about running a gas gun in PRS because why not (I need to keep myself entertained).

I have an older DPMS (Gen 1) 308 that runs. As with all things, AR related, the obvious solution is get a 22" 6.5 creedmoor upper. (I shoot a lot of 6.5 manbun already)
Problem--none of the uppers are compatible with each other, and finding the right DPMS upper could be a problem. That's option 1:

Option 2 is rebarrel. I've done light work on my bolt guns, but AR is more intimidating. TBH I just wanna fn shoot and not mess with the crap.

Option 3 is buy--probably a seekins or maybe a JP/GAP. Lets be honest--I'm not in the running for any wins or class leads, so anything over a seekins price is wasted money.

My goal is to have a running setup that I don't have to F with, just clean it, reload shoot, repeat. Advice on how to proceed would be appreciated. For a barrel like I mentioned 22" heavy barrel, and I do like the seekins handguard for barricades and whatnot. ANy other things to watch for for quality of life? AGB worth it? I generally run a brake in comp, but I do have a can and I know the ARs get fussy.
+2 length system?
Triggers -n- crap I've been doing forever.
Not a super fan of side chargers simply because I've used the "standard" AR-15 style. I can learn (I had to reteach myself to shoot left handed).

Input and cheap shots are welcome
Click to expand...
For option 3 Is there a reason why you are sticking with a large frame AR instead of small frame with something like a 6 ARC barrel (less recoil to spot misses, etc. but better in wind vs 556/223 Wylde)? Or do you want more velocity than what 6 ARC in gassers get you (2500-2600ish)?

If I was building a PRS gas gun I'd look at doing the above. Get a 20+" heavier profile barrel in 6 ARC and pair it with an A5 length buffer system and if running a can definitely get an adjustable gas block or gas key (Rubber City).
 
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#4
hlee said:
What model 308, specifically? If it’s the 24” bull barrel lr-308, run that. Mine is precise enough for a hobbiest shooter not hunting PRS match wins. Otherwise, rebarreling a lr-308 is arguably easier than rebarreling a bolt gun.
Click to expand...
Its a 16" 308. But just reading maybe I should just stfu and go shoot that. Matches I attend rarely go past 700 and max out at 800.

I though rebarreling a bolt was idiot proof--ARs are just as easy? I must be missing something.
 
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#5
DocRDS said:
Its a 16" 308. But just reading maybe I should just stfu and go shoot that. Matches I attend rarely go past 700 and max out at 800.

I though rebarreling a bolt was idiot proof--ARs are just as easy? I must be missing something.
Click to expand...
To re-barrel an AR it's kinda similar to a barrel nut prefit for a bolt action except the headspace is already set. You take the upper receiver and slide the barrel extension (which is already torqued onto the barrel for you 99% of the time) into the upper. Then you secure the upper internally via the lugs with something like a Midwest Upper Receiver Rod (use the 308 version if doing AR-10), etc. (which act like an action wrench to secure the upper before torquing the barrel nut on) then torque barrel nut to spec's listed by handguard manufacturer (usually 35-55 ft-lbs). If you feel the barrel extension to upper fit is too sloppy/wiggly you can add some loctite 620 to the barrel extension before sliding it in then let cure for 24 hrs before shooting. This will remove any slop once it cures.

The caveat to this is if you have a "thermofit" upper, it's a little undersized on purpose so that you can't just slide the barrel extention into it, you first have to heat the threads of the upper for a little with a heat gun etc. then you slide the barrel in.

Here's a few videos I put together showing how to torque the barrel nut on (you can watch the entire 6 part series if you want to see all of my upper build steps from beginning to end).




Once the barrel is installed into the upper all you have left to do is attached the gas block, handguard, and muzzle device
 
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#6
Get an AR reaction rod for the barrel swapping or installing muzzle devices. Makes it super easy. Put the rod in the vise and then slide the upper on it.

And yeah I would just go shoot what you have before spending money on building something. See if you like it first. Some don’t like semis. I said what the hell and got a 6 ARC upper and it’s a blast to shoot in matches. See if you like the .308 and go from there. Might just be as simple as a barrel swap for you.
 
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#7
I'd agree to just go shoot what you have -- you already know the rifle. It will give you a sense of its long-term usefulness in PRS if you just go shoot a trial match with it.

I shot my first two PRS matches with gas guns, first was 20" 6.5 Grendel and second was 18" 6 ARC. Windy western match site and the 6 ARC served me better in the switchy and gusty winds. I didn't mind running the Grendel first time out as I was just trying to get a feel for what the match setting is like, what the time pressures were like, etc. Semi-auto was easier for me on time management but not as good a choice for collecting hits over the whole match. I am not trying to place highly when I shoot PRS so that works for me.

I shoot a bolt gun 6.5 Creedmoor now, but I will shoot a small frame gas gun again next year.
 
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#8
If I were you: get out of the trouble of DPMS adaptations and buy a reliable complete upper like Seekers - plug-and-play, robust and not too expensive.
Rebarrel = work and migraine; sideloader passes if you want to learn, but stay on the classic AR style if you prefer simplicity.
Take 22" heavy, comp /brake + compatible silencer, + 2 length if it suits you for comfort; no need for JP / GAP unless you want to get on the podium.
 
#9
Gas gun unlikely to get on the overall podium in a PRS match, regardless of the roll mark on the receiver. But, 3rd place gas gun is a real possibility, unless there are only 2 gas guns at the match…
 
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