I was having difficulty with my PC soft lead cast bullets getting shaved while seating. I prefer soft bullets because they are easy on steel plate targets. I tried de-burring the case mouth and using the Lyman M die with some success but still was getting shaving and some barrel leading. As a test I made a sizing buttons for 45acp at 0.455 diameter and 9mm at 0.360 diameter that were long enough so the bullet could be set in the case with only another 0.050" push required by the seating die.
Shaving disappeared and accuracy increased! Even with only minimal neck tension I had no difficulty with bullet jump and the barrel looked much cleaner indicating good powder burn.
With case springback my long expanders gave 0.452-0.453 for my 45acp bullets sized at 0.452 and the 9mm cases sprung back to 0.357-0.358 for a 0.357 sized bullet.
I know neck tension is important for rifle bullets to get the slow powders burning properly but is it that important for fast pistol powders?
Anybody else experiment with this?