Quote Originally Posted by Graemevw View Post
mine is 1979, .177, single sided safety, leather piston seal and 3mm tp.
Gun had never been apart before i got it.
From the outside the port looks normal, but from the inside it sort of looks like its been sleeved.
It might just be a burr on the edge of the hole though, hard to tell. Im sure weihraich werent sleeving down ports.
I had a 1978 .22 HW35 Export, a very nice example. Power was under 10 fpe with a new standard spring (leather seal). On closer inspection there was a tiny lip of metal on the inside end of the transfer port, looked like the drill bit or whatever tool they used had not quite gone all the way through. So I found a metal drill bit of the right diameter and gently twisted it through the port and cleared the lip. I think it was occluding about 10 per cent of the port at one end. Result? Without any other changes this liberated 1.5 fpe. So make sure your transfer port is open at both ends - COMPLETELY OPEN!