DCL_Dave on leather post-WW1 Gem piston seals

DCL_Dave on leather post-WW1 Gem piston seals 

Dave, in answer to a question whether all Gems had washer-less pistons or some Gems used leather piston seals, said:

Some later post-WW1 guns like the FLZ composite type Gem patterns were fitted with a leather cup seal but I have also seen other types of seal used including stacked flat leather washers and even jute string wrapped around a boss on the piston face.

Interestingly, Jean Marck Gem patterns of post-WW1 were still using machine fit hard steel pistons. I once had a completely original JM no2 Demi Tir that would hold a consistent 4fps variation over the club's chrono, it was the one of the most consistent guns at the club.