when one over shims or installs to thick of a breech seal in a
Diana 460M or a Diana 48/52/54?

Let's see what we come up with or discover.

Herb

you can bend the compression bar out of shape if you overdo it, have seen it and have corrected a few guns that were adjusted to overcompress the seal @ the breech.

I do not know what can happen in the 460, I still need to get mine to study it fully. But I would think that the cocking lever might pop open before it should. Not good at all.

Breech seals are like other seals, they should "tighten up" the more you put pressure on them. Sure they need to start from a fairly closed position, but you do not need PCP type seals in a springer, the sudden surge of pressure will do a lot to seal the breech.

That is why I recommended to blow INTO the rifle (making sure THREE times it is uncocked, unloaded and empty each time). If pure lung pressure (1.5 BARS from a healthy male) cannot seal the breech and piston, then there is something wrong with the sealing and it has to be checked. Bit by bit: the breech, then the piston.

If people won't listen to simple advice (what can be simpler than blowing into the rifle?), then they are better off doing their heart's content, whatever that is, whatever that costs.

JMHO





Un Abrazo!




Héctor