12ga black powder loads for old shotgun

[Microairman1]

So I picked up a old shotgun for a very low price but was told I can only shoot black powder shells thru it as it has an older Damascus steel twist barrel (think I got that right). Am I right in saying that?

So the next part, if that's true, does anyone know safe loads for 12ga using black powder? Anything special I should know about loading with black powder vs modern smokeless powder?

 

[Wolfhound]

There is some black powder load data available on the internet. Be aware that some of the old shotguns have short chambers so a 2 3/4 shell might be too long.

Be ready for a bunch of smoke when you fire it. Lol

Be sure to clean it right away as black powder creates a corrosive residue. Soap and hot water work well.

Here is a link to some good information http://www.tbullock.com/bpsg.html

 

[bobjones223]

I would think you could use a modern powder with a lighter charge with the same result and not have to deal with all the issues involved with black powder.

From what I have read if you stay in the 5000-6000psi range you "should" be safe.

I searched "Vintage Shotgun Load Data" and came up with several using Remington and Winchester 209 powder. Might be something to look into so you don't have to deal with black powder unless you just want the "cool" factor of a smoke cloud drifting in the breeze in which case SMOKE ON!!

 

[Microairman1]

So how would I know if it has a shorter chamber then normal? Is there a way to check?

Depending on how hard it is, I think it has a certain cool factor. Even if I don't use them all the time. Might be neat to have for it. Especially with the big smoke cloud lol

 

[Wolfhound]

Chamber Length. Many old guns have short chambers. You will have to trim the modern shells to fit. If a long shell is fired in a short chamber there will not be room for the mouth of the case to open and the pressure will increase dangerously. Shells are measured while open; not when crimped. Old barrels are seldom marked with the chamber length; you must measure them to find out. The modern 2 ¾ inch shells were introduced in the 1920's along with the star crimp.

Forward Chamber Diameters
Gauge Inches mm
.410 0.463 11.76
28 0.614 15.60
20 0.685 17.40
16 0.732 18.59
12 0.798 20.27
10 0.841 21.36
Some of the common chamber lengths were:

16 ga - 2 9/16 (pretty common)
16 ga - 2 3/4 (modern star crimp)
12 ga - 2 1/2 (English) Now called 65mm.
12 ga - 2 5/8 (very common in America)
12 ga - 2 3/4 (modern star crimp) Now called 70mm.
To measure the length of a 12 gauge chamber make a metal bar 0.798 inches in diameter; the size of the forward end of the chamber; and about 3 inches long. Slide it into the chamber and measure how far it goes in relative to the breech face. Round that down to the nearest standard size. Don't guess! Consult a gunsmith if you can not perform this absolutely indispensable step by yourself.

The table gives the chamber diameters at the forward end, just where the mouth of the shell lies after firing. These are the modern minimum SAAMI dimensions.

A simple chamber length gauge may also be made from a bit of heavy sheet metal. This one is double ended; the pictured side is 12 gauge and the other side is for 16 gauge.

Also note that old shotguns often have chambers that are shaped differently from modern ones. Here is a Cerrosafe chamber cast of a Parker gun made in 1890. There is hardly any forcing cone; the chamber simply ends with an abrupt step at 2 5/8 inch just like a rifle chamber. It's diameter at the case mouth is right at the modern minimum of 0.798. This is meant for a brass shell.
Cerrosafe is a bismuth based alloy that melts at about 180°F. Just hold the barrel horizontal, clap a bit of wood at the breech with your fingers to make a dam, and pour it right in. Avoid the extractor. This makes a nice cast image of one side of the chamber and you can see the reamer marks and rust pits and everything. Get it at www.brownells.com.

 

[ol' poke]

Once you get the chamber-length figured out, and find hulls to fit, charge them with 4.4 cc's (the biggest Lee dipper) of Goex. add a nitro card, a fiber wad, the same dipper filled with shot, and cap it off with an overshot card. KA-BOOM!

 

[Alpo]

I shot a lot of black powder shotgun at one time. 1 oz of ffg, 1 oz of shot, Win WAA12 red wad. I normally used Remington hulls because they slid out of the double barrel quite easily.

 

[Wolfhound]

Back in my younger days I went dove hunting in Alabama with a couple of Army buddies. One of them had a bunch of black powder shotgun shells a relative had given him and he wanted to use them up. Watching him on the other side of the field blasting away in a huge cloud of smoke was one of the funniest things I've ever seen. I was laughing so hard I stopped hunting and just watched him.

 

[Slow Hand]

There is a lot of good Info on this site:


Black Powder Shotgun Shells

i haven’t loaded BP shotshells in awhile but unused to shoot them in CAS. If you are planning on shooting more than a few rounds, finer wads are much better than plastic. The plastic wads can slightly met as they go down the bore and You will have a ‘snake’ of plastic lining your bore. Ask me how I know!!

Also I second the chamber length deal. Also twist and Damascus barrel can start to rust between the layers of steel and that is generally impossible to see. So you are literally taking your safety into your own hands when shooting an older shotgun with those barrels. I had good luck with both of my old remingtons, a 12 ga 1889 and a 10 ga 1882! Fun stuff.