Will this load stabilize in a 1:9 or does it need a 1:7/8?
Will this load stabilize in a 1:9 or does it need a 1:7/8?
What is the barrel length? The longer the barrel is and the higher the velocity is, the more you can get away with on slow twists.
Just the same, a 7 would be preferred, with 8 being borderline acceptable in my opinion.
It shoots ok in a 1/8 twist RRA NM barrel I have... pretty well in fact, 1-1.5 MOA if I do my part.
18in. Barrel seems to shoot fast. My Win 55gr FMJ stays around 3150fps (Spec is 3270 from a 24in) so I'd imagine this load would run around 2600ish.
1/7 would be better for a variety of reasons.
Facts matter...Feelings Can Lie
Actually, up to 1/9 is very useful, it just usually comes in substandard quality guns. The 1/7 twist was adopted solely because some wonks thought it would be a great idea to have the capability to shoot M856 tracer in the gun. 1/9 will stabilize the M855 load, but not its companion tracer round, so along came the 1/7. BTW, it was never intended for M855 (Green Tip) to be a standard service round for the M16/M4, but only in the M249 SAW. Since we've trended much heavier in projectiles for the caliber, I guess it turned out ok.
Regional Government Sales Manager for Aimpoint, Inc. USA
Co-owner Hardwired Tactical Shooting (HiTS)
Faster twists have some significant external and terminal ballistic advantages as a result of faster rotational velocity--this is especially important with both shorter barrels and longer ranges. Of course the projectile must be robust enough to handle the increased forces without coming apart in flight...
Last edited by DocGKR; 10-09-2018 at 08:59 AM.
Facts matter...Feelings Can Lie