Home Forums Hunting & Shooting AR and Tactical Rifles AR-15 twist rates

I bought a used upper from a pawn shop. It seems to have a 1-8.5" twist rate. Did they make such? I put the cleaning rod in twice and measured 8.5" each time on a complete revolution. If it is 1-8" or 1-9" or 1-8.5" what are the optimum bullet weight ranges? I wanted to shoot heavier bullets for deer hunting. It shoots good with 55g reloads that a friend gave me his dad reloaded back in the early 80's using ball powder. Oh, got it for $250. Can't beat that. Rifling looked real good in the store. Someone must have needed the money real bad. I got a complete DPMS lower for $250 new and a $100 colt bolt assembly. So I think I did good building my own. Back to bullets. I wanted to shoot Barnes TSX or Nosler Partitions, the right grain for optimum penetration and expansion. Most deer around here are killed less than 150 yards.

IIRC Olympic did an 8.5 twist and I believe that Obermeyer also did at one time. IE I"m 99.9% sure I"ve seen that figure before. Consider that a true full 9, driving hot loadds, will stabilize a sierra 80 smk out of a 20 inch tube.... the 8.5 will also, so should easily stabilize the 62 barnes and I don't really see the need for the heavier barnes and from what I hear the lighter version may work bette rthan the 62 on deer even....

Barrel is a 16" barrel. So, I think I agree, the 62gr Barnes should work. I've read the 165 gr barnes works as good as a 180 gr standard bullet out of a 30-06. Seems reasonable. How do you guys think it would work with a 22lr adapter?

Keep in mind that the weight of the bullet is not what matters when considering twist rate, but rather, the length of the bullet. A all-copper bullet will be longer, grain-for-grain, than a bullet that contains lead within the jacket because lead is heavier than copper. Hence, a 53gr or a 55 gr Barnes will be as long or maybe longer than a heavier cup and core or bonded bullet will be.

I have heard of really good results with the 53 and 55 gr Barnes, and I have personally had good results with a plain old Winchester Power Point 64 gr hand load from my 18" barreled 1 in 8" Wylde chambered AR on medium sized deer. The largest deer around here don't get like the northern deer do, size wize.

I have yet to recover any of the 64 gr bullets, but I have limited my shots to 225 yards thus far and have had complete pass through results.

I have picked up some of the Barnes to load, but I have not taken the time to get around to actually loading them as of yet. Come to think of it, I haven't even measured them yet either. I am in the middle of moving my loading stuff to a new barn out back, and deer season is upon me, so I had to re-prioritize again. Time to fill the freezer for winter (and hopefully next summer too).