Took Chamber Casts of both Armi Sports Sharps and Navy Arms Rolling Block

[cpt dan blodgett]

Sharps Chamber Cast
Rim thickness . 070
Distance from rim front shoulder to break at end of chamber. 2.055
Total depth of chamber 2.125
Diameter .484
Distance from Rim front edge to front break  2.100
Diameter  .462
Distance from Rim Front to start of rifling .2.210
Groove diameter  .0458
Bore  .450

Remington Chamber Cast
Rim thickness . 070
Distance from rim front shoulder to break at end of chamber.2.060
Diameter .486
Total depth chamber 2.130
Distance from Rim to break at  bore 2.140
Diameter .462
Distance from Rim  to start of rifling   2.198
Groove diameter  .0458
Bore Diameter.  .450

Sharps has pretty sharp angle at end of chamber.  Remington RB Navy Armys Pedersoli has a shallower angle. Resulting in longer freebore but a overall shorter lead as start of rifling is about ,012 closer to front of rim than in the Armi Sports Sharps.
Must have done a decent job of measuring was able to find a pedersoli sharps chamber drawing and they have a 2.129 spec vs my 2.130 measurement

Bottom line are the chambers far enough out of spec to cause problems to the extent i need to stretch brass say .015 - .020, trim down 45-90 to 2.120 sharps and 2.125 remmy.   Full lenth size a few times to grow brass?  Or just not worry about it
2.125 Sharps
2.130 Remmy  

[Otter]

I have 3 - 45-70s (Shiloh Sharps, Original RB w/ new barrel & 1895 CB lever) and one 45-90 Shiloh Sharps. I have not done a chamber cast on any of them, at least not yet. I trim the 45-70 cases to 2.10 and the 45-90 cases to 2.40 and have had no problem getting any of them to shoot where I want them to (assuming I do what I need to do).

I'd say just don't worry about it . . .

[Steel Horse Bailey]

Keep on shootin', Cap'n Dan!