AR-15s...

[Nash B.]

I'm looking for some ideas for my last 3 lowers. I've already built a cheap .223 carbine and have a .458 SOCOM upper on its way. I'm thinking I'd like something capable of long-range shooting - what would be the best cartridge for that (in a magazine-fed AR)? Then I'm thinking of something like 6.8 SPC but I'm not too sure about that since it's already gone through like 3 different spec revisions, or 300 Blackout (from my research it's best enjoyed in a suppressed SBR). Anything else worth considering?

[whitetrash]

long range .308

[Nash B.]

long range .308

Not in an AR-15. I'll eventually get a Savage or Remington 700 in .308 or .300 Win Mag too...

[dee]

6.5 Grendel or just plain 223 pushing the heavy bullets or better yet 6x45 similar weight bullets yet higher bc's

[whitetrash]

cj has a ar in .223 going 1000 yards.

[TEAMJACOB]

You can sell me one

[bottlerocket]

6.8 SPC is a great round, but as good as it is long range, its more developed to get the most out of the bare minimum meaning better terminal performance out of a carbine length or shorter barrel.

[Nash B.]

I'm just looking to turn 1 of the 3 lowers into a long-range gun, in whatever is the best cartridge for that with an AR-15. I know CJ does .223 out to 1,000 yards but he also says the wind drift is bad; just wondering if there's a better cartridge for that while sticking with an AR-15.

Then I'll still have 2 more lowers to build just for general use, and thinking about 6.8 SPC and/or 300 Blackout and/or any other interesting cartridges.

[motoman]

I'd recommend a 300 whisper if you have any plans for a suppressor.

[ThreeFingerPete]

I'd recommend a 300 whisper if you have any plans for a suppressor.

Have any other brilliant recommendations? 300 whisper at 1000y will drop about half of a mile. You would need ~100moa of elevation adjustment to make shooting at 1000 any better than guess work.

[motoman]

Have any other brilliant recommendations? 300 whisper at 1000y will drop about half of a mile. You would need ~100moa of elevation adjustment to make shooting at 1000 any better than guess work.

No where in my post did I mention 300 whisper for a long range rifle, I specifically mentioned 300 whisper for the thoughts of running a suppressor. The OP mentioned having 3 lowers, 1 he'd like to build for long range, leaving 2 left over... hence my suggestion.

[ThreeFingerPete]

No where in my post did I mention 300 whisper for a long range rifle, I specifically mentioned 300 whisper for the thoughts of running a suppressor. The OP mentioned having 3 lowers, 1 he'd like to build for long range, leaving 2 left over... hence my suggestion.

Ahh, because he specifically mentioned looking for a long range round.

[Chopped54]

For long range you are kind of limited with the short lower. I would look into a 204, 224, or 22-250 24" upper.

[motoman]

Ahh, because he specifically mentioned looking for a long range round.

Then I'll still have 2 more lowers to build just for general use, and thinking about 6.8 SPC and/or 300 Blackout and/or any other interesting cartridges.

And I rest my case...

[ThreeFingerPete]

And I rest my case...

Im sure he appreciates an input on a toons you've never loaded or fired.