N/A Diana 6 Breech Seal

DIA300763


Googling is fun and easy!
 
now the model 5-5g-5g mag and 6-6g-6m model 10 all have something most guns do not have and that is shims under the breech seal
i have found none to as many as 4
and after saying that not all Orings are the same size, oh yes they are the same size but in a tolerance
you may have shims and don't know it already or haven't looked
the shims are .11mm thick
now why does this matter and the answer is the pistol could shoot high or low after the breech seal is changed and if you don't have extra shims like most of us don't use a layer of Dental Floss
will you need to do this maybe not but be aware that you might
 
I do not know if I have shims under the breech seal yet. I figured I would replace the seal and see how it shoots. I acquired the gun recently and it does shoot a little too high with the rear sight all the way down. I was thinking that I could buy a cheap metric hole punch set and make the shims from plastic if needed. I am aiming about a half inch down below an 1 1/4" bullseye at 21 feet.

Thanks for the tip about dental floss.
 
I punched out a seal out 0.019 (19thousanths) inch plastic. It proved to be too thick with the gun shooting about 8 inches low with the rear sight set high. I tried punching seals from 0.005 but was unable to cleanly so far. So I thinned the seal some by sanding it on 320 wet paper to the point that gun shoots a 1 1/4" lolly pop center sighting to the base of the circle with the sight set high. As the seal wears, I will compensate by lowering the sight.
 
It would be a nice thing if there was a database that contained o-ring sizes for various pellet guns.


that would be easy wouldn't it, i for one have been chasing Oring sizes for me and other for a decade or more
measuring Orings is hard no matter what but a set of calipers and a stainless 6 inch ruler will help you get close
you will find a stainless-steel rule is the best tool you will have General NO.311.me