Finnwolf:
The only formula I have talked about came from the Late Charles Davenport, and that is his formula for determining how much black powder can be burned in barrel of a given length. Now, I can only assume he was thinking of rifle barrels, because shotgun barrels are often made of much thinner stuff, and hold less pressure. so be careful with this.
The formula for finding the maximum load of BP you can burn efficiently in a barrel of any caliber and length is: 11.5 grains per cubic Inch of bore. Assuming a bore diameter of .729 for a 12 gauge shotgun, the nominal diameter, my 30 inch barrels can burn 144.00 grains of powder efficiently. That is near 5 and 1/4 drams of powder, and that is a lot! I would never consider loading that much powder in those barrels.
Your 32 inch barrel would fire 153 grains of powder. Again, I would never suggest using so much powder, particularly in a light gun. The barrels may take it, but will the stock, and your shoulder?
Again, in BP shotguns, with a cylinder bore, Less is more. Read V.M. Starr's article in Bob Spenser's Black Powder Notebook to learn about loads for shotguns. [url]
http://members.aye.net/~bspen/starr.html[/url]
Bob Spenser also has his own article on loads, there.
You were talking about getting your barrel jug choked, but didn't mention what size of choke. Assuming you take ROUNDBALL's lead, and go for a full choke, you will probably have a 40 yard turkey gun. I will still recommend 2 3/4 drams of FFFg powder, ( 76 grains) and 1 1/4 oz. of #5 shot, the harder ( ie. plated ) the better, for long shots, and the best patterns.
I use this same load, using smokeless powder equivalents, in my modern shotgun with its Full choke, and throat-relieved Trap Barrel to shoot long range targets, and the load patterns beautifully. I have starburst clay targets out at 50 yards with that same load, and even the shooters shooting against me wanted to know what the heck I had loaded in my gun to break a clay target at that range, so hard.
When I told them this is an old market Hunter 50 yard Duck Load from the Illinois River back in the 1870s, and 1880s, they just shook their heads. Everyone of us has loaded much more powder and even more shot for long range shells for our trap guns, and they were all surprised at how little my powder charge was.
When I got my Percussion shotgun going, I began shooting a light trap load. Then, before hunting season started, I went ahead and loaded it with the #5 shot, 2 3/4 drams, and 1 1/4 oz. of shot, to see how it would pattern, and shoot. I got, and get, nice round patterns, that are nicely filled out. My gun is still a 30 yard gun, but those pellets can kill much further than that. As I indicated, I have killed a pheasant at a measured 33 yards with that load from that gun.
I would not take a shot at a turkey at 40 yards with that gun, simply because I believe the pattern gets too thin at that range to insure a good hit in the head or neck, or both. If I can choke the load with paper shotcups, so that I get denser patterns, I may be able to stretch that 30 yard limit some for turkey hunting.
My inclination now is that if I were going to go after Turkey, I would use my 20 ga.fowler, and I know that barrel has enough metal on it, to allow me to jug choke it, for that purpose. I just don't know if I want to spend that much effort to shoot a turkey at 10 more yards.
Hunting for me is about being there, and out witting the game, to get close enough. Getting a turkey into my shorter range is what makes the hunt a thrill, not just killing a bird. I would like to take a turkey some day, but the world won't end if I don't. That means I can pass on the longer shots. Its just as much fun for me to take any BP shotgun out to shoot doves, and pick my shots. I might not shoot my daily bag limit of 15 birds, But I will have a very good time trying.
I was worried a bit that it would knock the snot out of Swampy... :haha: not worried at all after I shot it though.
