View Full Version : AR Barrel Twist Rates

12-03-2006, 6:35 PM
I know questions regarding barrel twists on AR rifles come up from time to time and I saw this on AR15.com.

By Corey Sattler (Webmanager@olyarms.com)
Here is the info I have collected for .223 twist ratios from various sources (including in-house testing & ammo manf. contacts).

1x7 - technically too tight of a twist for any .224 bullet widely available, including the 80 gr. Manufactured originally to stabilize SS109 and/or tracer ammo, but further military testing has shown other twists to be superior. Some of the very heavy custom stuff (87 gr?) may work well, but why????

1x8 - great twist for 69-80 gr bullets. Sierra once informed me that the perfect twist for their 80gr was 1x8.2xxxxx (blah blah blah big long engineers explanation followed).

1x9 - good all around twist ratio. Best suited for 52-69 gr, but either end of the envelope will be questionable.

1x10 - practically the same as 1x9, but favors the lighter side a little more.

1x12 - great for the 40-52 gr bullets. Most often found on bolt action rifles as their primary use is varminting. All right for the 55 gr, but not the best.

1x14 - if you want to understabilize the .224 bullet, use this twist. Useless except for tumbling effect it causes upon bullet impact. IMHO, better to shoot straight with a good HP bullet as your chances to hit are better and damage will most likely be greater also.