My exposure to high power rifles has been mostly directed to target rifles. Back when I was whole, I started with an M1903A3NM, graduated to an M1MkII, then an AR. I managed to earn my NRA XTC Master classification with the AR. My AR service rifle is a post ban Colt Match Target A2 with a 1:7 twist. I would shoot magazine length 77gr SMK out to the 300 yard line. At the 600 yard line, I preferred 80gr SMK loaded singly. I was told to expect a target accuracy life of about 5000 rounds.

After my accident, I built a 1:8 twist Frankengun AR with the intention of shooting 1000 yard F class. That is still a work in progress.

Over the course of about 25 years and numerous discussions in the pits at Perry, the concensus has been that for service rifle competition, either a 1:7 or 1:8 barrel is a necessity in order to be competitive at the 600 yard line. For me, a 1:9 barrel just can't be competitive beyond the 300 yard line.

This summer, I am looking at adding a twist to my shooting. Having been a right handed shooter all my life, I am looking to shooting my AR match rifle and service rifle left handed, because I need to get back on the game I have grown up with.

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Judge control not gun control!

For me, an AR is an AR is an AR. I've owned a number of them from Colt, Ruger, etc. (The Sterling AR-180 doesn't count, but in my mind it was a much superior rifle.) The only AR-15 platform I have now is a cheapo ATI Omni Hybrid with a 1:7 twist rate. I don't expect it to be an MOA bullseye rifle, and it isn't. Just as I don't expect it to last forever, unlike my expectations for my hand-built Marlin-Ballard .22 lr Schuetzen rifle.

Though I've nailed my share of deer with an AR, I have long since relegated them to varmint control, both four- and two-legged varieties. The Omni came in quite useful about 4 hrs. ago when I spotted a big ol' raccoon staggering (obviously diseased with who-knows-what) down my fence line. I don't even recall offhand what loads are in it right now, but I flipped on the reflex optic, set on the finest green dot, popped it off safe and planted one in it's neck at 75 yards.

The raccoon didn't care what the twist rate of the barrel was, nor the bullet weight or it's composition. And I guess I don't much care, either. It did what it was supposed to do with decent accuracy, and that's all I can ask of it.

Now, that Marlin-Ballard, and my bolt guns... well, they're an entirely different story.

I went 'round and 'round with that notion.
I really got sucked in and put on a 6.5 twist for 90 grain bullets.
Theoretically, it should shoot like a 175 gr .308 but in practice it does not.
And the pit crew hates looking for the small holes.
At midrange, it is a different story, it is a FINE 600 yard rifle.

I now think your 8 twist and a fast 75-82 gr is the better approach at making a Long Range .223. So does Eric Stecker.