[Coltdriver]

Does anyone know or know of a source for determining optimum rifling twist for a 220 swift?

Assume that the bullets would be 40 to 50 grains max.

One fool on this board is thinking about building one and needs to know:D

[Jagermeister]

What ever the twist, the ctg. will have to be married, (tested) to determine which ctg is best for the twist.

Build it, test it, (marry the ammo)

HJN:D

[BigG]

I would hazard that 1:12 would be enough with 50 gr or <. The M16 was in that flavor and stabilized 55 grain enough to get sub MOA accuracy. Generally, the heavier the bullet, the quicker the twist. That's why the 62 grain gets spun at 1:7, particularly as the tracer round is so long. HTH

[Art Eatman]

Suggestion: Check the various factories' websites; see what seems to be most common.

I imagine that the majority of folks who shoot a Swift are varmint hunters, and that the majority use bullets in the 50-grain to 63-grain range. I'd think, therefore, the factory twists work best with this range of weights.

Just guessin',

Art

[swifter]

Most come 1:14, stabilizes 40-50, most 55s. when I repipe my .220AI, I'll go with a 1:10 or 1:12 and shoot somewhat heavier bullets a bit SLOWER...:D
Tom