Mr. No Gold,
I thought the same thing about a brass plate as I've owned some other rifles with the same set-up. This one, however, does not show any evidence on the finish of ever having a plate, at least for any length of time. I'm wondering if the screw holes were a later addition by a previous owner?
Another interesting feature- the ramrod hole does not extend past the rear entry pipe. The ramrod is purely cosmetic and would seem to be done merely to meet the requirements of some of the old matches that specified that the rifle must carry a ramrod. The hole hasn't been plugged-I thought that might be the case-it was never drilled.
I think that the barrel being hand forged is another strange detail. It is big- 1.425 at the breech and 1.380 at the muzzle- and I would have thought that given the gun is late in the flintlock period that Boyer would have done the barrel from a bar. Maybe the barrel was from an earlier rifle?
It is .487 on the land, .522 in the groove, seven narrow grooves with a 48" twist and a perfect bore. It was fit with a rear peep sight, typical of the period. That was missing but is soon to be rectified. The first three shots fired from the rifle all overlapped by half at 60 yards. It's been in three turkey matches here and won them all.
Winning matches is something I think this old girl is used to doing...
Steve