AR-10 build. .260 or .308?

[Garvey]

I've shot a couple thousand rounds of .308 bolt gun. Comp rifle/ hunting rifle. I rebarreled it for .260 and will never go back. But I have a lower and will be slowly building an AR-10 just because I can. I have dies and powder for both cartridges. Just don't know which way to go with the AR-10.

It'll be a hog thumper, and of course a fun range rifle. I'm aware of barrel life of .308 vs .260 but I still can't decide.

 

[Cobracutter]

Re: AR-10 build. .260 or .308?

Sounds like you know the awsner already. Would be nice to find a .260 load that both rifles like to make it easier. Since you are reloading .260 sounds good.

My next big bore Ar is going to be a .260. Might want to look into 6.5 creedmore as well.

 

[thorbird]

Re: AR-10 build. .260 or .308?

I will be doing a .260 too. Just picked up a DPMS 20" barrel for My Mega Maten Set. Look forward to playing with it. What barrel do you think you'll go with? The 8 twist seems to be good for the .260 for a wide range of bullets. My DPMS barrel is a 1 in 8.5

 

[Garvey]

Re: AR-10 build. .260 or .308?

I have a 24", 8.4" twist Obermeyer for my bolt gun. Its shot 130 VLDs at 2950fps bout .25 MOA. I switched to 140 A-maxes (to save barrel life) and they shot at 2800 fps around .15 MOA.

Just can't pick a side of the fence for the AR. The .260 is a ballistically superior chambering in velocity and BC. But the .308 sure does deliver the whoop ass when it hits soft tissue, and the barrel lasts much longer.

P.S. I won't barrel for 6.5 Creedmore. It is way to close the.260 and there's no sense in buying new brass and dies.

 

[rezman762]

Re: AR-10 build. .260 or .308?

If your already set up to reload the 260, I say go for it. Worst case, you not satisfied with it you could quickly turn the lightly used 260 barrel and go back to a 308 tube. I'm doing it a little different and just building an extra upper in 260, just waiting on the barrel. I looked hard at the 6.5 CM but don't want the hassle of chasing down the somewhat hard to find brass. I can make 260 if I have to out of 243 or 7mm-08 brass.

 

[Redmanss]

Re: AR-10 build. .260 or .308?

Correct me if I'm wrong as I'm a factory ammo shooting guy, but isn't there an issue with .260 restricted to mag length in the semi autos, hence why many prefer 6.5CM? I seem to recall reading that before.