A fast twist barrel will cause the SX bullets to come apart. I have had vapor trails and disintegrated bullets with them in a 1 in 9 barrel. Supposed to keep velocity under 3500 fps, but I ran them at full velocity in a Ruger #1 in .22-250 with no issues and my cousin ran them full throttle in a .220 Swift. Both barrels were 1 in 14.
yeah, they certainly will come apart in a one in 12 twist when pushed hard... and even leave a vapor trail almost out of the barrel..
definitely when you use a 1 in 9 twist...
have watched a vapor trail, when it was in the high 90s or triple digits here in Oregon... with a crystal blue sky and low humidity...
and then if the remains hit a target... looks like the target was shot with a 410 and number 5 or 6 shot.
