doublegunshop.com - home Forums General Discussion Double Rifles, Paradox Guns & Gauge Rifles @ doublegunshop.com Made a chamber cast for my 12 bore double rifle.

Grooves measure .740 and the lands .730. The bullet would fit snuggly in a papercase. Now to find out if it was made for a bullet or ball. Barrels look like about 3/8ths of a turn in 25 inches. Just guessing but that is about 1 in 72 or something isn't it? The gun weights just under 12lbs. So I assume its made for ball. What size of lead ball should I begin the process with? .730? Anyone know where I can buy some lead balls of the correct size? Or better yet an order with two or three sizes in it. I don't really want to buy a mold until I find the correct size that will regulate.

3/8 in 25" is about 1:66, which is definitely a round ball twist.

Ballistic Products sells a ball, about .730 I think, that fits into a 12 ga. shot cup. I would definitely check their web site.

If you want to load an unpatched ball, you need a ball no smaller than .740, and .741 is probably better. Smaller, and the hot gas will melt the edges of the ball between the ball and barrel, causing poor accuracy and bore leading.

Thanks Carl.

Yes, .741" would be ideal, but you'll have to get some brass cases from Grafs.com. Also, lube the balls with Lee Liquid Alox. 12ga slugs would be better, used with a shot cup in the plastic hulls, then you wouldn't have to worry about leading. Lyman's slug casts .704" and LEE's cast .685". If your gun was designed for black powder, then maybe you could just buy some slug loads up there and reload them.

I have a few slug mold that would probably work. They cast bullets in the 700-770 grain range, and diameters of .740-.742"
Email me at gksappington@aol.com and we can discuss it.

A 1 in 72" twist should shoot a short bullet of about .900" in length without trouble. I just had a 1 in 84 twist made to shoot my 770 grain Truncated cone slug.
Greg