[Aus]

I have been interested in the Double Tap 9mm ammo and see it runs the same fps as the .357 sig.
Glock has a 15.98 length of twist in .357 barrels and my question is, how does the 9mm bullet do at higher velocities out of a barrel with a 9.84 twist?

 

[Stephen A. Camp]

Hello. I've shot some fairly stiff loads in 9mm with the generalized 1:10 twist and had no accuracy problems. The fastest I've shot has been 88 and 90 grains at approx. 1500 ft/sec with 124's and 115's following at about 1300 and 1400 ft/sec, respectively. These were from Browning Hi Powers and a GP Competition. I've fired the same loads from a 6" STI Longslide Trojan, with 1:16 twist and noted no overall difference in accuracy or expansion. I suppose it could be due to extra pressure build time, but the factory Hi Power twist from the 6" GP Comp barrel produces speeds roughly 100 ft/sec faster than the Trojan...at least in my guns.

Expansion testing in water, wet pack, and tissue (from javelina to deer) have resulted in no big differences in recovered bullets.

Best.

 

[Aus]

thanks.
and no problems with extra fouling?

 

[Stephen A. Camp]

Hello. No, not with jacketed ammo.

Best.