help with baikal proof markings

[thehunterman]

I have a older 20 gauge baikal single shot and would like to know if it is rated for 3 inch shells? the main markings are 20x76 and I'm assuming that the 76 is the max length of shells to fired in the gun thereby meaning 3 inchers would be fine but I want to make sure first there is also a marking of 15,7 not sure what that one is,anybody know?

 

[Lodi]

You are correct on the "76" being mm and chambered for 3" shells.

Sorry on the second part, I don't have an answer for you.

 

[gunsaholic]

I believe the 17,8 is the bore diameter which is .618. 20 gauge bore can range approximately anywhere from .615 to .629.

 

[thehunterman]

thanks guys