AR-10 AR308 Platform Cartridge Options

[Old Jeff H]

I wanted to think on this for a couple of days, and let people with more knowledge than me reply before I did.

IMHO, if you want an AR style rifle, and you want parts/ammo/components that are readily available and relatively cheap, I'd just stick with 308. Plus it has compatibility with your M1A.

However if you want to get serious about shooting 1,000 yards, and doing so competitively, I'd be looking at a 6 or 6.5 bolt gun.

[BigNate]

I wanted to think on this for a couple of days, and let people with more knowledge than me reply before I did.

IMHO, if you want an AR style rifle, and you want parts/ammo/components that are readily available and relatively cheap, I'd just stick with 308. Plus it has compatibility with your M1A.

However if you want to get serious about shooting 1,000 yards, and doing so competitively, I'd be looking at a 6 or 6.5 bolt gun.

Thanks Jeff... I'm looking at this specifically for Accurized AR match stuff. I've got an AR-10(T) and a build based on a PSA 223 Wylde upper - both of which I picked up from car buddies... Right now I'm shooting the .223 for economic reasons (cost of match grade rounds) but my OCDishness is kicking in and I'm thinking about what I can build that will give me faster, flatter with longer legs... I picked up a bare Aero M5 lower a while ago that sits in the safe and every time I see it I feel guilty that it does not have parts added so that it is more than a paper-weight... LOL.

I've also been toying with putting together a long range bolt gun - but that will probably be something in a cartridge that can stretch even further. No clue yet what that will be - but guessing something in the range of cartridges between .300 WM and .338 Lapua - thinking .300 PRC, .300 Norma, etc. but no clue where that will actually land other than that I know that I don't know. That will be a research project for another month (or year)...

[BigNate]

If you're taking a .300 WM to let kids mag dump, well that's on you. I only take my Nemo Omen Recon out to shoot flat and hit hard at long range with my precision shooter friends.

https://nemoarms.com/product/omen-recon/

One of my friends in the PRC game in VA, absolutely swears by the .260 for it's extra case capacity. He shoots his large frame Larue a lot. The only reason he has sidelined it, because the 6.5 PRC has that case capacity that so often loves but can only do it from one of his AI bolt guns.

I've recently got another form 1 back. I was going to leave it as is as a spare but am now going to turn it into a mini recce using a 12" Faxon 6mm ARC barrel, using a JP Grendel II bolt paired to an NP3 Sionics coated MIcrobest carrier. Not a large frame but something to consider as that round is very flat and even at 300 yards, it's still cooking at over 2,000 FPS even from a small 12 incher.

Thanks - good information. .260 Rem is currently at the top of my list. I've got a local friend that built one and loves it.

[Yugmoto1]

I built my AR-10 inn6.5 creedmoor, not because I think it's the best thing ever, but it is fun to shoot and when I built it I bought bulk s&b cheaper than I could find .308. But that was then. But if you're going to compete, and load for it I guess you gotta pick the one that works for you best. I planned to use mine as a hunting rifle when I can, I built it light enough, and the 6.5 is nice enough that my wife likes to shoot it as far as recoil goes. She didn't like the 308. Is .260rem more difficult to use in the AR-10? As far as fit and function? The 6.5 was easy.

[Yugmoto1]

.260 is interesting, I think you can get a bit more out of it than the 6.5 maybe. But I'm not at that level. As long as it works and that's what you're after it'd be worth a look.

[TheAccountant]

260 or even a 260AI without mag length restrictions is one thing, but the design is a bit dated for the modern high BC bullets. In a short action magazine setup or AR10/LR308 you wind up having to either seat beyond the neck/shoulder junction or go with shorter and/or lighter bullets. The 6.5 creed and 6.5x47 really shine in mag length setups.

[dkizis]

i have a ar-10 in 243 and it is a tack driver if i do my part.

[BigNate]

.260 is interesting, I think you can get a bit more out of it than the 6.5 maybe. But I'm not at that level. As long as it works and that's what you're after it'd be worth a look.

From what I've read - you can get between 100 - 200 more FPS out of the .260 Rem than 6.5 CM (in gas gun loads).

[G34]

i personally love fast 6mm
6.5 will do both though also. run 147s and then switch to 123s for velocity if need be.

without a doubt once you get more experienced in putting together these AR10/LR308s youll learn JP High Pressure bolts are a must. I highly recommend JP SCS also.

[QuangTri]

without a doubt once you get more experienced in putting together these AR10/LR308s youll learn JP High Pressure bolts are a must. I highly recommend JP SCS also.

I am sure the JP site has great things to say about their bolt, what have you found to be superior in use rather than a generic .308 bolt?

[G34]

the firing pin and firing hole are undersized to allow less primer flow with high pressure. This is an extremely common problem with large frame ARs. if you haven't had this occurrence your very lucky. the ejector is smoothed out on all edges so less ejector swipe happens.

in my recent experience and the ppl that i shoot with AERO and Ballistic advantage are loose on the tolerances. i have had issues with others but have the actual data on these right now.

[QuangTri]

That is what I was looking for , thanks.

[428cj]

For me it would be the 308.

[samnev]

Guess I'm just old fashioned. When I bought my last AR 10 I was tossing around getting a 6.5 Creed. But decided since I'd need new brass and ELD projos, and with 4350 so hard to get I just stuck with my 308 Winchester. Ended up buying a Les Baer Swat Sniper with a NightForce 5-25 Atacr. Still shooting 168grain SMK's that I have a life time supply of and more 308 brass than I'll ever need. Never been sorry about the decision especially since I don't shoot any further than 500 yards.

[Blue109]

My buddy has ARs chambered in just about every conceivable round, and his .260 is probably my favorite gun ever. It's boring on our short course (300-650yds) completely dialed and almost impossible to miss. Such a nice smooth gun. Does well on the long side (800-1200)

Side note....just for science, I put a Franklin Armory binary trigger in my 16" 308 and it runs flawless lol. Good clean fun.