going from hoots info in 24 twist to a 16 twist is REALLY going to change the RPM on those - which is going to decrease the velocity these bullets will be able to handle before failure occurs. i dont know *WHERE* that fail point is... however lets do a little math...
rpm = Muzzle Velocity * 720 / twist rate
hoot's 2500 fps in the 24 twist = 75000 rpm
2500 fps in a 16 twist = 112,500 RPM
thats a 50% increase in the rpm... to maintain a similar RPM in the 16 twist would limit you to around 1675 FPS. (1675 * 720 / 16 = 75,375 RPM)
and we're discussing a bullet designed to work at 900 fps out of a 5" barrel... or roughly 40,500 rpm (assuming a standard - or from what i can gather is the standard twist - 1:16 twist 45 acp pistol)
so while running them at 2500 fps in a 24 twist represents a 85% increase in RPM over their intended spin, doing so in a 16 twist is at the same FPS translates to a 278% increase in RPM over their intended usage
If we *ASSUME* (yes i know... loaded statement) that this bullet's intended terminal velocity is 800 fps to 1600 fps (Like the 250 xtp is) that gives us an operating RPM range from 38000-72000 rpm. so right upwards to roughly the top end of hoot's testing. I'd have to contact hornady to find the specific's of the bullets design specs, but the fact that its holding up at 75,000 RPM @ 2500 fps leads me to believe that its about the right numbers anyway.
hornady has also likewise advised on the 250gr xtp (#45200) is designed for max use in 45 colt applications. as such their concern is more about base deformation leading to pressure spikes when fired at higher rifle velocity's. I'd have to imagine a similar caution should be taken with the 200gr XTP as well.
just some food for thought. as always play safe and work up slowly and remember to have fun along the way
Edited by Hoot to change https... to just http... in the image link