Vol423,
Thanks for the info.
The fitting procedure described by Heym20 applies to Zimmermann full length, adjustable at the muzzle ELs. The more traditional 22mm and 44mm long rimfire ones are more like my description. I suspect some are imported installed in used drillings and later separated and sold alone.
Mike

Last edited by Der Ami; 05/01/18 04:13 PM.