A BPCR rechamber conundrum

[RWE]

Here's a chamber schematic from a cerrosafe mold I made from an old barrel.

It's probably a 44 Henry rimfire which had a case length of about 0.9" and an OAL of 1.345" with a 0.446 heeled bullet.

The dimensions shown are probably +/- a 0.001, because I expect the chamber should have fit that 0.446 bullet even though the casting measured 0.445, but that's what I got.



Anyway, the conundrum.

I want to rechamber the gun without setting the barrel back any if possible, and use the bore/groove as is considering it will take a 44 cal lead bullet nicely. I can fit a cartridge with a OAL of about 1.6" max which is represented by the thicker unlabeled line.

***All blackpowder loading****

A 44 special will clean up a lot of the old chamber, but leave a leade/throat of 0.125" at 0.445 diameter and the tapered section of 0.105" down to the threaded bore, essentially a total of 0.23", most of which is 0.015" larger than bullet diameter.

A 44-40 will clean up the old chamber up until where the neck meets the shoulder of the 44-40, then it will be overrsized by a thousandth up until the last 0.08" of the tapered section where the chamber measures about 0.444. I assume more throat would have to be cut to properly seat without jamming a bullet in the lands? What diameter would you cut it for?

A 44 mag will clean up the old chamber all the way to the start of where the lead tapers, essentially leaving the 0.105" taper. Same as the 44-40, I assume more throat would have to be cut to properly seat without jamming a bullet in the lands? What diameter would you cut it for?

What are my pros and cons for the scenarios given? Any other scenarios pop into your head?

[country gent]

Check the bore groove dimensions on the barrel also. If its .446 groove then the modern inside seated 429 bullets will be to small for it.

[RWE]

slugging the bore gives the 0.428+/- and 0.418+/-.

Kind of made me thought it was a 42 allen rimfire, but that would have been a way oversized chamber...

Of course, swagging a lead bullet in the chamber from 0.446 down to 0.428 seemed kind of odd as well, but it may have been the case.

[country gent]

A lot also depends on the rifle and action type. Chamber for a round that factory loads are over pressure for it is a distinct problem. While you state BP only what happens when the rifle is eventually out of your control?

[RWE]

Well aside from taking a precaution to stamp the barrel "BP only", I believe my wife will bury me with my projects, so the concern is moot.

[John in PA]

I'd re-chamber to .44-40 WCF. Vintage cartridge, plentiful components, matches bore diameter well. The chamber reamer will cut proper throat and leade for the designated cartridge.

What action will the barrel be installed on? .44-40 is used on plenty of N-SSA competition original guns that were OEM chambered for .44 RF, Ballards, Wessons, etc. with perfect safety. BP or very mild smokeless loads only in those weak actions.

[RWE]

A steel framed Ethan Allen drop breech. (Allen & Wheelock)

I mention steel because some were made in brass.

All were originally rimfire actions, but chambered in 44, 42 and some in various 30 cals. They are late civil war vintage.

[RWE]

And doing more investigation on chamber dimensions versus cartridge dimensions, John, I believe you are right. The 44-40 will fit it better, and the bottle neck, albeit a small one, will facilitate loading and unloading the 44-40 which is about a quarter inch longer than the original chambered round.

[John in PA]

Bob Hoyt, Freischutz Gun Shop in Fairfield PA, does a lot of chamber and barrel work for N-SSA members, and has rechambered MANY original s to .44-40 WCF.

[rfd]

+1 on bobby hoyt's work, excellent.