Originally Posted by 3rdgeargrndrr

Thank you all for the suggestions.
XTP diameter is .3565. I could not measure the cannelure diameter.

I might have found the culprit of the spinning bullets.
Cases are fully sized. I exclusively use winchester 1x fired nickel plated brass. 1.2855”. *Edit: for full house defensive loads
I tried on regular winchester brass which is slightly longer at 1.2857”. Dies were probably set up with this case years ago for hard cast medium loads.
The xtp projectiles dont spin on the regular brass or it takes a good firm grasp of the bullet make it spin.
Which leads me to believe that :
1)There is 0.002” less crimp
2) nickel plated may have less friction and allows the bullet to spin in the roll crimp.
I dont have any other jacketed bullets with cannelures to test out.
And this of course does not happen on hard cast.
Attempted to upload a gif but it was too big.