Rich Hollis & Sons Shotgun, English Made

[B Tom]

Based on this photo you provided, a #11 cap is what you want to use.
The nose of the hammer isn't large enough to work well with a musket size cap.

Thank you Zonie. I think that is a fair assessment. #11 seems right since the existing nipple top stack OD is about 0.165" (but having too much taper downward). One of the fellows suggested the hammer may not be an original and appears offset to the nipple. So, if this is the case I hope the hammer won't give me any grieve once I install

.
Glad you got the nipple size sorted . All English sporting shotguns and rifle used 1/4 and 9/32 BSF thread I would say that the BSF thread for nipples first became used after the patch lock period of 1810-30.
Feltwad
A Early Patch Lock to Percussion Conversion fitted with a 1/4 BSF thread

Hmmm. I learn something more every time I log onto this website. Thank you

.
Glad you got the nipple size sorted . All English sporting shotguns and rifle used 1/4 and 9/32 BSF thread I would say that the BSF thread for nipples first became used after the patch lock period of 1810-30.
Feltwad
A Early Patch Lock to Percussion Conversion fitted with a 1/4 BSF thread

 

[B Tom]

Based on this photo you provided, a #11 cap is what you want to use.
The nose of the hammer isn't large enough to work well with a musket size cap.

Thank you Zonie. I think that is a fair assessment. #11 seems right since the existing nipple top stack OD is about 0.165" (but having too much taper downward). One of the fellows suggested the hammer may not be an original and appears offset to the nipple. So, if this is the case I hope the hammer won't give me any grieve once I install the new #11 nipple.

 

[Rudyard]

Rowntree ' Invented the copper cap ' along with a number of other claimants,But Rowntree clearly did have a flair for inventiveness as this gun boldly suggests . The side plug 'drum & nipple' being uncommon on a new percussion gun in England seemingly he used a older flint barrel restocking it with this unusual lock perhaps the ' patent' he in this case is claiming . Very interesting gun and in good hands Regards Rudyard