Quote Originally Posted by T 20 View Post
As far as I can make out, Tone, they're the same stroke as the HW50, so about 65mm, which would tie in with John Walther's Airgun book which tells of a HW55 model that used a HW50 cylinder and barrel latch ?

Hopefully I can stretch the stroke to around 72mm but I may be able to go a little more, it's very difficult to give an exact figure until I've measured everything up a few times.
I can't work measurements from the HW50 I have in bits as I have a 99 barrel on that which moves the cocking lever about 3mm forwards of it's normal position.

All the best Mick
How long has your stroke ended up Mick? I seem to remember that you bad some breech void issues?

I have a mild case of the flu, so been tested for covid, and not allowed to leave the house for some days until the test comes back...

Which means I have some time to work on the old rusty HW50s!
I had an extra piston, and has machined it down as much as I dare, plus added a steel seal converter so the piston can take Diana/AA seals.
Had to lengthen the cocking clearance in the piston a few mm's and the stroke is now somewhere between 73-74mm.
Put in a brass tophat from another HW50 project, and a ARH/JM E3200 spring.

The gun behaves quite well during firing, but I have no idea how fast it shoots, as the chrono in in a box somewhere...