Quote Originally Posted by T 20 View Post
A 26mm cylinder/piston assembly will fit.

I'd try putting a pellet in the barrel but leaving it's tail hanging out then closing the lever --- if the pellet is pushed fully into the barrel it tells you if the transfer port is hitting the barrel.

If the pellet remains proud of the barrel then the crown could be the problem --- easiest solution is to machine the crown on the cylinder back.
Now that is a really clever idea!!

Thanks for that.....I'll give it a try