I went on the NBC (National Bullet) Web Site and found that the 158 grain bullet I'm using has a Brinell Hardness of 18 (7% Antimony and 2% Tin mixture).
I also talked with a Lyman Rep. who confirred with their bulleticians and the most critical dimension I gave them were the cylinder exit holes of .3575".
Based on that they recomended a Sizing Die of .358. They said it was important that the bullet does not "rattle around" when leaving the cylinder and entering the barrel's forcing cone. the .0005" touch was enough to accomplish this.
I'm working with Lyman right now as to what Top Punch would fit the NBC bullets. Lyman's Top Punches are made for thier Molds so we have to find the best fit of Top Punch to NBC bullet.
I appreciate all the information so far. I've received a combinztion of information from all the Boards I've posted on that say:
Increase the FPS & decrease the FPS with the same powder, switch to a slower powder, try a different Lube, Lube should not effect it that much, size the bullet diameter down, leave the bullet diameter at .359".
My plan is to:
1. Re-size the bullets to .3580"
2. Use less Unique powder for lower FPS
3. Use more Unique powder for higher FPS
4. Try a slower powder.
5. Try VtVorhe (spelling) #110
Thanks for all the information to date. Keep it coming if anyone has anything else to share. - J.Solo