All,
I'm new to the forum, and have done quite a bit of reading as a lurker since I've got into casting. From what I've read, it seems like most leading issues are caused by undersized boolits, with less probable causes being lead hardness and lubrication.
I am currently having leading with my 9mm P226. The barrel slugs out at 0.3562-0.3564". During my initial loading, I was getting pretty considerable leading. I have since chased the issue down to the boolits being swaged down when seating to ~0.352". I have since gotten Lathesmith to turn me a custom expander at 0.356", and that seems to be helping a lot with the boolits not swaging down when loading. The lead I am using is dead soft ( pure lead) and am powder coating with Harbor Freight Red. The powder coated projectiles pass the smash test. The mold is an Accurate 35-147c mold and casts at 0.358" prior to coating. I then powder coat and size to 0.3575".
Using the custom expander, after seating, closing the case mouth to 0.379", and pulling a boolit, the boolits are 0.3565", so some swaging is still taking place.
I have two outstanding questions:
1) Would a smooth sided projectile be better for powder coating when sized 0.001" or less larger than bore size?
2) Should I increase the diameter or the lead hardness at this point? I assume the harder the lead, the less swaging will go on and the resultant diameter will also increase.
Just for info, my load is 3.3Gr Alliant Bullseye with the projectile seated at 1.145" OAL. They chrono graph approx. 900 fps, and are ~23ksi according to QL.
Thanks!