Fitting new Gem spring -ouch.

[Benelli B76]

A lot of Gems never had seals they relied on a good fitted piston and the use of oil, I have come across many that have a leather washer in the bottom of the cylinder to minimise metallic contact when fired, the fact that the piston was hardened probably meant that no seal was ever fitted.
Instead of fitting a seal to the front I've found that grinding a groove behind the head and fitting an "O" ring
Improves the usability somewhat.

Thanks for that, it makes sense. I wonder why there is a hole drilled in the piston head, unless it was used to centralise in manufacture. Mine was only doing 330 fps when I bought it so I think the leather buffer I removed was blocking the transfer port. Much smoother to cock and shoot now, and I am amazed at the tight groups for the smoothbore. Going to have fun with some darts (plastic covered type).

Baz