- Joined
- Oct 21, 2017
- Messages
- 504
The nice thing about polymer seals which form the piston head is that they provide a soft buffer as the piston reaches the end of travel, when BSA used steel O ring piston heads in the 1970s and 1980s they incorporated a polyurethane buffer between piston and head.
I've machined O ring heads from Polyurethane for older air rifles and pistols, for a Weihrauch I'd be inclined to use PTFE and machine it properly to either press fit onto the piston, or use a "Keyhole" slot allowing the head to be installed or removed with the piston out of the bore by sliding it sideways but retaining it securely whilst in a bore where sideways movement is restricted.
Using screws to hold a head on a Weihrauch piston is at best a kludge and lacks engineering imagination and knowledge of air gun history :-(
I've machined O ring heads from Polyurethane for older air rifles and pistols, for a Weihrauch I'd be inclined to use PTFE and machine it properly to either press fit onto the piston, or use a "Keyhole" slot allowing the head to be installed or removed with the piston out of the bore by sliding it sideways but retaining it securely whilst in a bore where sideways movement is restricted.
Using screws to hold a head on a Weihrauch piston is at best a kludge and lacks engineering imagination and knowledge of air gun history :-(