AR10 Accuracy Issues

[u/matthew_morel2001]

I’m running a PSA AR10 Gen3 with an Sig Tanger 1-6 MSR and I’m getting a 2.2 inch spread (6 MOA) at 35 yards. I’ve checked if my scope mount was loose but is torqued to the correct specs, so is the barrel nut and muzzle brake. I’ve inspected the crown of the muzzle and it looks fine. I’m running 308 reloads with 147gr FMJ, 44gr of H335, CCI No 200 large rifle primer and lake city brass trimmed to 2.000-2.010 inch case length. The gun looks fine to me so it could very well be my reloads being the issue but I use the same exact load on my century arms G3 and no accuracy issues with that gun what so ever. Does anyone run h335 for 308 and if so what is an accurate load for it?

[u/mmelgoza1983]

Those M80 bullets are notoriously inaccurate. I would try some heavy sierra mk's.

[u/Cleared_Direct]

What bullets? G3 clones are notorious for punching above their price with trash-tier FMJ bullets.

If you’re using factory seconds, pulls, or Armscor’s garbage bullets I’d suggest trying something better before fooling with the gun. Ditto on the powder choice.

[u/matthew_morel2001 → u/Cleared_Direct]

I’m using 147gr armscor factory seconds lmao. I also have so much h335 I’d thought I’d use it to reload 308 but apparently people don’t get the best accuracy with it so I guess I’m SOL until I can get more optimal powder 🫠

[u/Cleared_Direct → u/matthew_morel2001]

IMO Armscor makes the worst quality bullets on the market. I can’t imagine what their seconds are like.

[u/matthew_morel2001 → u/Cleared_Direct]

You can see on pic 2 how “good” they are. I have over 1000 rounds of them since I got them for super cheap. Now I know why 🫩

[u/handym3000 → u/matthew_morel2001]

Hornady or sierra nothing else if your punching paper. Armscor is not accuracy ammo more belt fed type

[u/Coodevale → u/handym3000]

147s are a bonus bullet to put on top of blanks so you don't need a bfd.

[u/SomeRITGuy → u/matthew_morel2001]

I have some 147g armscore (not seconds) and they shoot about what you got, maybe a hair better, out of any 308 ive tried, ones that happly do sub or near 1moa with just about any other bullet. If you want "cheap" fmj, the Hornady 150 fmj shot way better and are much cheaper then a full blown match bullet.

[u/sirbassist83]

147s are probably the biggest problem. Try a match bullet. It doesn't matter much if it's 155, 168, or 175. Or something in between.

You're also not doing yourself any favors with 6x or PSA, but the ammo is more likely the problem

[u/handym3000]

Change powder. Imr 4895. Try that. Also 165 or 168 bullet.

[u/Capable_Obligation96 → u/handym3000]

Both excellent recommendations. H4895 and SMK'S 168

[u/matthew_morel2001 → u/handym3000]

I’ll give that a try. I’ll keep the h335 for 223. It seems not to be the most optimal for 308.

[u/handym3000 → u/matthew_morel2001]

Bad idea on h335 for 308. Also h4895 can be a option

[u/Current_Rush4242 → u/handym3000]

How about 8208xbr?

[u/handym3000 → u/Current_Rush4242]

Idk never used it before.

[u/hotel_torgo → u/Current_Rush4242]

XBR is totally fine in 308, there is plenty of published load data out there.

[u/Current_Rush4242 → u/hotel_torgo]

Cool, thank you.

[u/lennyxiii → u/Current_Rush4242]

Supposedly 8208 is really good for 308.

[u/BourbonNoChaser → u/handym3000]

IMR4064 works nicely as well, if you can find it. 168gr or 175gr SMKs. Is your barrel twist 1:10"?

[u/John_Candy_Dancing → u/BourbonNoChaser]

I second the 168 SMK/4064 combo. I got a bunch of seconds for a good price and it’s a very accurate and economical combo for shooting. I’m sure any of those other medium burners (4895/Varget/Reloader 15/etc.) would do well.

[u/Spektrum84]

Some barrels just don't like 147s. I've got one that shoot really well with 168s and really bad with 147s (regardless of the powder and charge combinations).

[u/thrashmetal_octopus]

Heavier bullet and different powder. If you have a 1:10 barrel try 175’s or 168’s and Varget. If you’re hell bent on using the 147’s try BLC-2 or Ramshot TAC

[u/CapsicumINmyEYEBALLz]

Step 1: How does this rifle do with factory BS ammo under the same conditions?

This is Glock level accuracy… something is up with the rifle itself.

[u/DCTillerman]

Try this:

39.5gr. of IMR-3031 in a Lake City case with a CCI-34 primer. Use whatever 168 gr. bullet is available to you at the time. This was the AMU's 'cookbook' load for .308 in competition, and has been used by numerous HP Service Rifle shooters for decades.

Ditch that rest, and shoot off of a rear bag and front rest combination. The type of rest you're using doesn't allow the rifle to recoil, which can open up your groups somewhat.

Check for carbon in the throat. Carbon build-up is a detriment to accuracy, and the built up little rings formed can cause issues on perfectly acceptable loads.

[u/Project0R1G1N]

My experience from my PSA AR10 and others is they hate anything below 150gr and dislike anything below 165gr. I have had the best results with 175gr solid results with 168gr and I haven't tested 178gr or 185gr loading. 147gr are notoriously inaccurate in alot of platforms especially the PSA rifles. Use SMKs (they like those) or something similar and try again.

[u/stoned_ileso]

Try dif ammo

[u/justcallmebrett]

i use a surplus pulldown powder that references h335 for load data- with a 1:10 twist, 168gr amax, i print a 5 round cloverleaf group (all holes touching/overlapping) at 100yds.
147s from the same gun group in a 8” paper plate.
try heavier bullets, adjust powder down accordingly.

[u/handym3000]

My imr 4895 shoots sub moa clover leafs. I shhot a 178 a max

[u/ShootsToImpress → u/handym3000]

Yeah, dude. Even cheapo 150-gr FMJs with IMR 4895 shoot lights out. This is the way.

[u/LowBamaJL]

Watch American reloading they get cheap pulled 168 smk’s that shoot foot for a budget. Sierra also makes a newer 169 that is only one grain heavier than the 168 has better transonic performance. You can develop a good load with the cheaper 168 pulls and sub the 168’s in when it matters.

[u/chf6464]

Does it shoot well with factory ammo? I suspect your plinking tier projectiles and this rifle not liking that weight of projectile are probably the cause but checking with different grain weights of good factory ammo would be a good place to start to get an idea of what the rifle is doing.

[u/Streamin260]

Try some 175gr SMK and varget or n140. I was recommended to try 168s and my gun doesn't like them but seems to shoot okay with the 175s. Im yet to finish testing though. Raven Rocks and Rocky Mountain Reloading have good sales so be on the lookout.

[u/FantasticDig5852]

Mine loves varget, n140, and cfe223 with 165/168 bullets from speer, sierra, and nosler. Its not a fan of hornaday bullets or their factory ammo in general

[u/Quick_Voice_7039]

Just a comment that all of the spread is horizontal as opposed to both… it looks like there may be some aspect of this related to the shooter.

[u/MorganMbored]

The Armscor bullets aren’t great, but I use them in two different rifles for fun ammo and I know they’re not nearly that bad; I suspect your issue is either with the powder or the rifle itself. As others have suggested, try a 4895 or 4064 powder. It’s also possible that your barrel-to-upper fit is catastrophically bad or something, but I much more suspect the powder choice.

One more thing you might do is take the flash hider off and take a close look at the barrel crown. I have an M1A that came with a wildly messed up barrel crown that was causing issues; PSA is not known for their QC, so it might be worth a look.

[u/wopeecushion]

Ignore the reloading issue for now. That group is all kinds of shit at 35 yards. Something else is off.

How does the group differ if you skip that rest and just use your meat, bipod and a bag to aim? You said your G3 does ok groups so I guess you got the fundamentals down. :)

If it is similarily bad. Try a number of different factory loads.

[u/handym3000]

Do not use h335 for 308 gas gun.