John Singer
Well-known member
I have a 1930s vintage Winchester Model 12 in 2 3/4" 12 gauge that I inherited from my grandfather several years ago. My grandfather was not a hunter, he was a farmer and the gun was a "barn gun".
The barrel was a 30" full choke. It originally measured 0.695". Using a hand adjustable ream, I opened the choke to 0.715". This made the choke a "light modified". It is, by far, one of the most useful guns that I have. I use it for nearly all my goose hunting and much of my duck hunting. For geese, I shoot either B or BB steel shot, for ducks, I use #2 steel. I have shot several pheasants with the gun using #2 steel.
I have also opened the chokes on (2) 16 gauge guns and one 20 gauge gun. As somebody previously mentioned, it is probably not best to aim for a specific measurement. It is best to work slowly, remove a little metal at a time, and then pattern the gun. Repeat until you get the pattern that you want with the ammunition you are most likely to use. I did this just recently for a guy that wanted to open a choke for a gun for ruffed grouse/woodcock hunting.
I opened the chokes on the 16 gauge guns so that they could safely be used with steel shot.
As others have also mentioned, consider having choke tubes installed. I suspect that Model 12 guns require the use of thin-walled tubes as the barrel walls are not that thick.
The gun would be more versatile with choke tubes. Being able to install a full choke tube for turkey hunting make the gun even more useful to me.
The barrel was a 30" full choke. It originally measured 0.695". Using a hand adjustable ream, I opened the choke to 0.715". This made the choke a "light modified". It is, by far, one of the most useful guns that I have. I use it for nearly all my goose hunting and much of my duck hunting. For geese, I shoot either B or BB steel shot, for ducks, I use #2 steel. I have shot several pheasants with the gun using #2 steel.
I have also opened the chokes on (2) 16 gauge guns and one 20 gauge gun. As somebody previously mentioned, it is probably not best to aim for a specific measurement. It is best to work slowly, remove a little metal at a time, and then pattern the gun. Repeat until you get the pattern that you want with the ammunition you are most likely to use. I did this just recently for a guy that wanted to open a choke for a gun for ruffed grouse/woodcock hunting.
I opened the chokes on the 16 gauge guns so that they could safely be used with steel shot.
As others have also mentioned, consider having choke tubes installed. I suspect that Model 12 guns require the use of thin-walled tubes as the barrel walls are not that thick.
The gun would be more versatile with choke tubes. Being able to install a full choke tube for turkey hunting make the gun even more useful to me.