Have you measured the rim cut?
I would match the gun with thick rimmed ammo
Mike
Yep.
Shell rim thickness has a wide tolerance these days.
The euro shells are sometimes thin. Might be within ‘spec’ but still a problem.
I would try a few boxes of Federal shells. The rims are on the thick side and the primer has a rounded profile.
You might also try handloads in Remington shells with Cheddite primers. They have a thin primer cover and are the most sensitive of all of them.
The Fox mainsprings are very strong, that was not likely to be the issue.
Old guns just sometimes complain about our modern crummy ammunition.
