Twist Rates

[Gos]

Greetings,
What twist rates are necessary to stabilize the new and longer 22 slugs that are showing up on the market?
Thanks in advance,
Gos

 

[Scotchmo]

Be more specific as to the slug.

Without knowing more details, for 32gr lead slugs, the common LW 1:17.7 twist is probably good. For 40gr slugs, I’d use 1:16 twist, or maybe even 1:15 twist.

 

[Stubbers]

Ideal twist rate is not solely based on weight, but rather a combination of projectile SG, projectile weight, projectile diameter, and projectile length. Hollow / longer designs would need faster twist rates than shorter designs of the same weight...

There are calculators out there to steer you in the best direction, as opposed to taking wag's. You can use the Greenhill formula or Miller twist rule to calculate ideal twist rate.

-Matt

 

[Scotchmo]

Ideal twist rate is not solely based on weight, but rather a combination of projectile SG, projectile weight, projectile diameter, and projectile length....

-Matt

Absolutely true. Though maybe not as critical, atmospheric conditions, muzzle velocity, and target distance might also be considerations when seeking the optimal twist rate.

 

[jps2486]

1-16 to 1-18.

 

[qball]

I ran the calculator and the superior heavy in .22 is good up to NSA's 35 grain slugs and not enough TR for 38 grain. I've tested them in my 1:16 heavy barrel and the results indicated the same, for 38 and 40 grain you would need 1:14 TR for optimum results.