I took my Sharps out for a day of shooting and got a big surprise.The cartridge would not chamber. When I removed the shell I noticed the nose of the bullet had been engraved by the lands. I measured the bullets just in front of the first band to get a reading on the nose since I had sized the bullet. There was a .003 inch difference between the bullets that fit and those that did not.
What could cause this? could it be differences in alloy , or the mould heating and expanding. The mould is a Lyman Postall bullet of 530 grains.