Twist Rates
The .223 Rem shoots a wide range of bullets very effectively, from 35gr flat-based varmint bullets, to ultra-long 90gr VLDs. However, you’ll need the right twist rate for your choice of bullet. For max velocity and accuracy with the lightest bullets, a 1:14″ twist may be ideal. More versatile is a 1:12″ twist that will allow you to shoot the popular 60-64 grain match bullets. (However, a 1:9″ twist is needed for the steel-core 62gr bullet used in the M855 military loads, because that bullet is as long as most 70-grainers.) For normal lead-core jacketed bullets, a 1:9″ twist will let you shoot up to 73gr bullets. Since most .223 Rem shooters prefer bullets in the 50-73gr range, a good “do-it-all” solution is a 9-twist, unless you’re a Highpower competitor.
For long-range match purposes, long, high-BC bullets are favored for their ability to buck the wind. You’ll want at least a 1:8″ twist to shoot the 77gr and 80gr MatchKings and 80gr Bergers. To shoot the new 90gr pills, a 1:6.5″ is recommended, though a true 1:7″ will work in most conditions.
Overall, what twist rate is best? For varminting we like a 12-twist. The slower twist will give you a bit more velocity, and minimize the risk of jacket failure at high rpms. For general use, an 8-twist barrel will let you shoot the excellent 77gr and 80gr Sierra MatchKings and nearly all varieties of non-tracer milsurp ammo. We’d only select a 1:7″ or faster twist barrel if we had a need to shoot the 90gr VLDs.
| Barrel Twist Rate | 1:14″ | 1:12″ | 1:9″ | 1:8″ | 1:7″ or 1:6.5″ |
| Max Bullet Weight | 55gr FB | 65gr FB | 73gr BT | 80gr BT | 90gr BT VLD |
to Jason for providing some cool photos, and to Sierra Bullets, for making its .223 Rem load data available.
Berger, Sierra, and Hornady also provided bullet samples.
info. available at accurateshooter.com