Seems like I read that the Pedersoli used a "tight" 1/4 x28. i just read that a few days ago because I recently bought a Pedersoli 12 double made in 1979 according to the date code. The nipples have square removal surfaces. My concern was the holes down through to the firing chamber look to be about .090 inch. My concern was hammer blowback.
Bob
They are metrics.That "tight" 1/4x28 is probably an M6 (6MM).Some of these
imported guns have case hardened breeches which makes it a gamble to retap
to the 1/4x28. Check the diameter with a properly calibrated micrometer and see
what it really is. If it's .236 or thereabout then it IS a 6MM.
The.090 flash hole would blow back hard in the long range muzzle loader Pedersoil
makes and I know they make a shotgun of the same profile.Good looking guns but
the rifles have sights installed.
Bob Roller