New Winchester Brass.
That is one of the reasons I started using Winchester Brass, I seemed to have fewer issues with the Swift Bullets.
I didn't do any special prep, just the normal belling the case mouth. I did try Tradmark's "454 crimp" process with these, but other than that same stuff.
For what ever reason, I definitely had more issues with the 265s, especially when I was using Starline nickel plated brass.
Edited by BBwheelgunner (09/29/18 12:39 PM)
"If you are going to go through all the trouble to put a hole in something, why not make it a big one?"