06-05-2018, 08:47 PM
bj139 Wrote:The original M16 was 1:14 twist then 1:12, if you wanted to be faithful to the original specs.
The only reason the prototype AR15s and the Colt 601s were 1:14 were because that's all that was made for .224" blanks for center-fire rifles at the time, mainly for the .222 Remington.
Cold Weather testing showed that 1:14 didn't stabilize well past 200yds, so they tightened the twist to 1:12".
All production models of the Colt 602, 603, and 604 had 1:12" rifling until the advent of the M16A2 in the early 1980s.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com