Choke Marking Help PLease

[Buffler Razz]

I have a 20 ga Zabalay with 3" chambers and am not able to determine the coke markings on it. I've seen this gun in a 12 ga and it was clearly marked on top of the barrels. Anyway I tried to take a picture but it does not come out to clearly so I resorted to old school and drew what is on the underside of the barrels & receiver block. One of he marks was a bit faint and I treid to show that by the scribble lines after the number 15.

Thanks!
Buffler Razz

[Delmonico]

OK, it's hard to explain if you don't understand choles, but the right barrel is cylinder bore, the first # is the bore diamiter, the second is the dia of the restriction.  0.0 mm  the third # indicates it has a flair, common in Europe, doesn't change anything.

The left barrel has 0.1 mm, don't have my conversions chart handy but convert that to 0,000's of an inch and go from there.

0.000 is cylinder

0.005 is commonly called skeet

0.010 is improved cylinder

0,020 is modified

0.030 is full

This is assuming modern plastic wads.  The best way to know for sure is a patterning board and the load you use, loads will vary.

[Montana Slim]

I get cornfuzled by the markings on shotguns....even American ones...or maybe I just don't trust them. So, I usually just measure the bore diameter, go to a reference on bore diameters, then figure .040 constriction (smaller bore) per standard choke increment. This is similar to what Del 's explaining.

European guns often have the chamber length in mm's listed as well.

Slim

[Buffler Razz]

Thanks Gent's. If my cypherin is right it looks like cylinder and somethin close to skeet in the other barrel. Should be good for those up close scattergun targets and flyers. I'll give the pattern board a go next time I'm up at the range.
Buffler Razz

[Delmonico]

You're right Slim, I had 12 gauge in my mind when I wrote that.  But the patterning with the load to be use is still the best prooff.