New P.P mold for 45-70

[bruce moulds]

randy,
on firing, before the bullet starts to move, it bumps up to whatever diameter the space allows.
for the part of the bullet in the case, this is the internal obturated diameter of the case.
the closer to that diameter the bullet is, the sooner it seals the gas, and the less it upsets.
these factors affect accuracy in a positive way if the fit is better.
old time match chambers took a patched to bore bullet with a friction fit into the case, and hence could not take groove diameter bullets.
modern groove diameter chambers can do the same with a dual diameter bullet.
i do not make moulds. am just afflicted by that surname.
have however spent some money on them over the years.
keep safe,
bruce.