I have an old Pointer shotgun made by yamato in 12 gauge, had no markings to show that it is a 12 nor does it say 2 3/4 ' or 3" it appears they copied the browning, need to find out what choke it is, any easy way to do that?
Am trying to post a pic I found on the web of one that looks like mine, only mine is in better shape.

They were pretty much a look alike (but no parts interchange) of the Remington M-11 which is a take off of the Browning patent. I would look for the asterisk on the barrel which is how Browning marked their barrels. One asterisk = Full, 2 Mod, etc. If a dash is added that would make for Imp Mod or LT Mod/Skeet 2 depending on the number of asterisks.

A general guide would be to use the barrel length with 26" being IC, 30" Full, and 28" being either Mod or Full. There is an old saying that a dime won't fit into the muzzle of a 12 fa full choke but I don't recall ever testing that saying. If I had a calipers I might measure the inside barrel diameter and subtract that from 0.725 which was a common bore diameter for Browning's in that era. 0.010" would be IC, 0.020" Mod, 0.030" or more Full.

The couple I have seen and all I have heard of were 2 2/4" chambered. If there were any with 3" chambers I haven't heard or read and I suspect few, if any, would have been so chambered.

These guns were planned to be imported by several importers such as Charles Daly, Garcia, Sloans, and a few others. Browning brought a lawsuit against these being made/imported which limited their numbers in this country. The attempts to import these look a likes curiously slackened and then disappeared when Browning and Miroku began talks about gun manufacture.

Thanks for the history lesson. I own a couple of Model 11s and never knew the Japaneses made them also.