BSA Knibbs meteor type breech seal

[Spitzer]

No. Flat edge goes into the recess, round edge seals against the main cylinder breach face. But either way works actually.

[stevegv8]

No. Flat edge goes into the recess, round edge seals against the main cylinder breach face. But either way works actually.

That's the way I'd prefer to fit it but thought the flat edge might pick up against the edges where the rounded looks to have a chamfer.

Thanks, will proceed as suggested