Mark D and Draitzer,

Guys, you are all fantastic! Thank you so much for this help.
I DID think that I was restricted to the 8 gram cylinders, but being unfamiliar, I thought it better to check before I went out and purchased a stack of 12 gm cylinders!

I have just received this Hammerli, so I am looking forward to getting to know it. Next thing for me to learn is the re-sealing process.

Pity there is no decent manual available for this old pistol, which would save me asking lots of dopey questions!
I do have a scan, one page of which was in my post above, but that scanned doc didn't answer my question as well as you guys did.

Cheers folks, and thanks again!
Mike