Tom,
Like all the .62, .69 and .72's we built, it was rifled 1:104. It had 8 narrow lands and wide grooves, and the rifling was about .006 - .008. Pretty much followed Forsythe's formula.
The 8 and 4 bores were the same configuration, except the rifling was a tad deeper at about .010 - .011" and 1:144".
For a powder charge, I used as a rule Ffg powder, sometimes Fg in the .72. Most always GOEX, although sometimes for hunting I kept a can of Swiss, but frankly I found that to be somewhat overrated through chronograph testing. I went with a 200 grain charge for the hunting charge, sometimes going up to 225. I had some customers report back to me that they were running 250 grains, but I never really got too excited about using that much powder in it.
What amazed me about the rifles was the ridiculously flat trajectory they had. For example, when I shot my buffalo, I was required to shoot it in either the neck or the head, so as not to mess up the lungs and/or heart. The USDA vet had to inspect each buffalo taken there. So, I elected a neck shot. I didn't want to mess up the skull. First shot was about 55 yards and he went down to his knees then got up and ran out a ways. Second shot was at 100+ yards. It hit the critter hard enough to roll him all the way onto his back. I think the ball deflected off his spine and came to rest on the far side against his hide. Then he got up and ran about another mile. What a rugged beast! He finally got tired and laid down. I came up to him and shot him again at about 10 yards, which did the trick. When he was skinned out, we discovered that the three shot group from three different ranges was about the size of a soda pop can top. All shots were taken at point of aim from a kneeling position. While I felt terrible about inflicting this much pain upon the poor critter, I was sure proud of the gun. It did its job just fine.
Topic: 8 bore "Afrikkans" rifle (Read 1342 times)