.58 Berdan RRB (corrected: .58 Roberts)

[ndnchf]

Tom - thanks, got it. I'm still waiting for my cases to arrive. They got sent to California instead of Virginia. They are on their way back to Connecticut, then will be sent to Virginia... I hope. This has been very frustrating. But unless another SNAFU occurs, I should have them late this week or early next week, The big question lingering now is if the thick case mouths of these lathe turned cases will accept a groove diameter bullet. I don't think they will, so I'll have to figure out a way to reduce the thickness.

[ndnchf]

I finally received the lathe turned cases for my rifle. I bought some .590" diameter, 490gr. minie balls to start out with. But the cases were so thick at the case mouth that I could not seat the bullet. So I had to bore the cases to accept them. I just did 5 to try them out.




Here is a dummy round next to a .56-50 Spencer for comparision. An unbored case an minie' ball are on the right.



I loaded them up with 50gr of Goex 2F and a Winchester Large Rifle primer. I have no loading dies yet so I had to improvise. Here are my 5 rounds next to a .32 Long Colt for comparison.



I went to the range yesterday and shot the rifle for the first time. The results weren't great, but at 50 yards they did make a group and the bullets did not tumble, so I consider it a success.



I want to try a shorter and lighter bullet that is groove diameter or better. But for now, I'll work with this.

[ehull]

Remember that at the breech end of the barrel the bore is .595 +/-, so perhaps your .590 bullet is not starting right. The Springfield rifle musket was rifled with a progressively shallower bore for the best use of the Minie bullet.

[ndnchf]

I don't recall the bore diameter, but groove diameter is about .594" at the muzzle and .602" ahead of the chamber. So my .590" bullet is quite small. Next time I may go up to 55gr. of goex 2f or try Swiss or Old Eynsford for a little more bump up.