Any MG-42 experts?

[Altarboy]

My son has painstakingly restored an MG-42 and discovered that it knocks the daylights out of the primers. He tested a couple cases with a new primer and no powder or bullet and both have a huge dent and backed out of the primer pocket a smidge. His 1919 also does this, but to a lesser extent. Any advice?

[Helen Keller]

of course the primer is going to do this with no equal flow of pressure.

no pressure to make the brass expand/seal the chamber

the primer is trying to propel itself in the direction of it's own thrust.

[Altarboy]

Hmm. Ok. Thank you.