AR style rifle with a 1/7 twist rate. What is a good bullet weight.

[Edmnushooter]

Just purchased a new AR style rifle with a 1/7 twist rate. One sight on the net suggests a 90 gr. cartridge is best. But obviously will not feed thru the magazine. I would like to know what ready made ammo would work best with this rifle for punching paper up to 200 yd's.
Thank you.

 

[bearhunter]

Just seat the bullet deeper and it will feed through the mag. When you are loading such a long for caliber bullet, your powder charge will be less and there will be lots of room in the case for the needed powder.

With such a tight twist rate, lighter bullets, especially being pushed over 3000fps may not stand up to the high rotation rate, because of the lighter jackets on the lighter bullets.

IMHO, bullets in the 67+ grain weight range will do every bit as well as the heavier 90 grain offerings. I would also shoot exclusively boat tails to increase the length of the bullet to operate better with that very tight twist. Milspec 55 grain bullets should do just fine.

 

[crashcollins]

The easiest to find would be anything from 55 to 75 grains. If your just punching paper the 55's will be the most economical but if your going for groups try Federal gold metal match 69's or some of the match 75's or 77's that pop up now and then. The heavier stuff is harder to find but it is out there.

My Colt 6920 really liked the Federal GMM 77's but they are expensive and hard to find so I end up reloading the heavy stuff. The Winchester white box 55's work decent in it for punching paper for fun. I did try reloading 75 grain Amax bullets but they have to be singly loaded because of the OAL and just weren't worth the effort for the shooting I do. They might work good for a long range shooting competition for really serious shooter's.

Good luck and have fun finding what works for you.