Update 9mm problems with cast boolets

[murf205]

One reason I was tentative about loading 9mm's was that I was under the false impression that the entire neck area holding the boolit had to be taper crimped. It stemmed from a lack of research in retrospect. When I realized, thanks to the very learn-ed people on this site, It only takes a small amount of crimp to do the job. In fact, if I had done what I had originally envisioned, I would have probably inadvertently sized the boolit too much and caused blow by=leading.

[fredj338]

There have been several comments about the amount of taper crimp to apply. I know too much crimp can cause pressure to rise. How are you determining light vs. heavy crimp? I thought the correct method was to have about .002" smaller OD at the crimp compared to just above where the base of the bullet is located. Let me know how you determine the proper amount of taper crimp on your automatic ammo.

1Iron

Imo, you cant taper crimp enough to raise pressures. It will more likely cause a loss of neck tension & reduced pressures.
If you go to PC, you should never have leading issues 9mm. I shoot my own PC cast in multiple 9mm, all sized to 0.357” with zero leading issues.