14 years ago I developed a 45 Colt Shot shell. You have the option of using 460 S&W brass or 308/30-06, depending on Rim or Rimless preference.
Cut brass length to 1.50" (same as 45 Colt overall length. Size in 45 dies and ream burs smooth! It won't chamber at this point because of the cylinder throat. I used a 44-40 die and gave the brass a slight bottleneck about 1/3 inch long.
Use a Large Pistol Primer, charge with 6.7 grains of WW231. IMPORTANT: put a 45 caliber cork or waxed cardboard card over the powder. This long case will now hold a full 1/2 ounce of shot. Place a second card over the shot. Some people roll crimp. Some people use Elmer's glue. Some people use paraffine. I use a roofing product Gutter Seam Sealer (in the roofing department at Lowe's or Home Depot). This takes 2 to 3 weeks to fully cure. The velocity will be 750-800 fps. Recoil is mild compared to a 1200 fps 410 in a hand gun!
Results: From a 5.5" barreled Ruger Vaquero, using 7.5 shot, a beautiful 12" even pattern at 12 feet (realistic snake distance). I wouldn't go bigger the 5's and that should tighten the pattern a small amount and each pellet will have more energy. 8's, 9's & 12's will be more scattered and each pellet has less energy. I used these while mowing with very good results. A friend used them while hiking in West Verginia on Copperheads. He had never seen a snake so torn up!
I still have some of my original batch that are 12 years old, and the shot still stays in place!
If you have to buy brass go ahead and do a whole 50 round box while you are set up.
If you don't have a $50 bag of shot laying around the house, either bum some off a trap shooter or sacrifice some old hunting loads. You won't need to worry about Standard, Magnum or Recycled shot anything will work.
You can work up faster loads, but for snakes and rats it isn't necessary. Just remember a larger volume powder charge requires a smaller volume shot charge.
Some lever actions cycle the rounds fine, some don't. You won't know until you try.
Ivan
If I still had 44-40, I'd use a 38-40 to neck the case, and reduce the shot volume accordingly. That should feed in the pickiest lever action too!
