Quote Originally Posted by ggggr View Post
Hi Mick---I meant making a full breech seal out of ptfe and then putting a hole in it, rather than actually trying to sleeve the transfer port itself. assumed that this would be ok as some people use ptfe to make breech seals for Cadets and Majors? Would hot air open up the hole in the middle if you more of less copied the Webley seal out of Ptfe but just put a smaller hole in it? The 4mm pipe would be handy for the centre of Webley pistol seals made of leather.
The trouble with the leaking hawks is that there are only about 2 threads on the plug, beyond the stock screw hole.At first I thought the stock screw hole was too deep but the air was actually coming around the thread. I think I used 271 loctite to sort it out.
I think the breech seal on the Hawk needs to be elastic, to deform as the breech is closed, then to return to its original shape to seal the breech. PTFE is not elastic; squash it and it stays squashed.

The other point is that Mick is reducing transfer port size to raise the compression ratio, which you would not achieve by restricting just the hole in the seal, I'm afraid.