Remington Rolling Block

[Stephen Borud]

Don the bore diameter is .396 and groove is .415. It has four lands four grooves. I couldn’t get a 44/77 case in the chamber but my little 40/50BN dropped right in. The chamber length is 2.415 with a leade that gets it up to right at 2.500 long. It has a 1/24 RH twist.

[Don McDowell]

Hmm, guess it's time to go digging thru my ancient Cartridges of the World book...

[Don McDowell]

Wondering if who ever did the work on that rifle way back when ran a 40-7o bn reamer into a Jarmin chamber?

[Stephen Borud]

Don I took one of my 40 cal pp bullets and slid it in the muzzle. It’s OD is at .398 it slid in right but went in.

[Stephen Borud]

Don I wonder if it isn’t the 10.15mm Jarmann?

[Stephen Borud]

I just saw your comment Don about the 40-70BN. Maybe so!

[Don McDowell]

The Jarmin is a real possibility, and it's not a lot different from the 40-70 bn..
Maybe run a 45-90 case in a 4065 die fill the case with 1f and a wad seat a bullet wrapped to .396 , rip the trigger and see what the fired case looks like.

[Stephen Borud]

Good idea Don. I have a friend that has a 40/65. I’ll see if he will give me a few rounds.

SB