4070 SS

[desert deuce]

fogman,
you need to think in terms of bore diameter or groove diameter, rather than greaser or pp.
and then what is the chamber for, bore dia or groove dia bullets?
if your chamber is for groove diameter bullets, you should be able to slip fit a groove diameter bullet in fired cases.
in actual fact most chambers are a little oversize, so the bullet needs to be a little oversize to fill the fired case.
a match bore diameter chamber should slip fit a bore diameter bullet.
keep safe,
bruce.

The rim at the mouth of the case frequently is rolled and requires deburring for a slip fit of any bullet, gg or pp, groove or bore diameter.

groove diameter gg bullets "should" slip into the mouth of a case whose mouth has been deburred if that case was fire formed in the chamber of that particular rifle.

Stick to the issue in the original post!

The issue here is a chamber cut for a .403" diameter bullet to fit a .403" groove diameter bullet barrel that has a .410" diameter bullet seated in a case fireformed in a particular .403" designed rifle chamber should not and probably will not slip fit a .410" bullet seated in that case fired in a .403" chamber. The cartridge will not chamber.

opening the chamber to slip fit a .410" bullet makes the bullet signicantly over groove diameter and greatly alters an otherwise original and valuable rifle.

Each rifle is sort of a law unto itself and before loading for it the bore and chamber dimensions must be determined and the bullet altered to fit the rifle, not the rifle altered to fit the bullet.