Reloading questions for 0.50 Rimfire Remington Rolling Block Carbine

[Patrick Chadwick]

Not .32" but what we Brits used to call 32-gauge or 32-bore. The modern use of calibre-12 etc can lead to confusion. Nobody imagines (I hope) that a 12-bore shotgun has a bore diameter of 0.12".

The Cal. 32 (CIP designation) shotshell has the following nominal dimensions:
Base diameter (very important) 14.55mm -0.15 tolerance
= 0.570" -0.006" Commercial cases are usually clearly under the nominal max. diameter. So I reckon it could be a good fit.

Rim diameter (not critical, as long as extraction works) 16.10mm =0.634"

Rim thickness 1.55mm -0.35 = 0.061" -0.014"

Length: from 50.7mm (32/50) to 70mm (32/70)

I have just measured a Magtech Cal. 32 brass case. The case mouth inside diameter is 0.532"-0.534" (not quite round). A .54 minié bullet will probably cast to something like 0.535", so with a bit of luck all you will have to do is cut the case to length!

And, of course, get a centerfire block!!!

[Patrick Chadwick]

The 2-line Remington address dates the carbine to pre-1872 (date of receiver manufacture, not sale).


The existence of a threaded plate to take the end of a cleaning rod is a very unusual feature in carbines, and should help to narrow down the customer that ordered it. Somewhere in the book there was a mention of just such a curiosity...

[Patrick Chadwick]

I do hope you are sitting very firmly on your chair. 2-band saddle-ring carbines were equipped with a cleaning rod. The only example of a single-band carbine with cleaning rod stop in Layman's book is from CAMBODIA !!!

"...The chamber dimensions suggest it fired an unknown .52 calibre rimfire cartridge with a case measuring 1 1/2" long and a bullet diameter of .517" ..."

Getting curious? Please post photos of ANY markings you can find, even if vestigial. I think you really need the book, and it would seem advisable to get in touch with George Layman who may be able to make a better identification than I can. And please measure and post the head diameter.


Oops! Sorry, I missed the thumbnail in your earlier post!

[Warwick]

Hi all of you fellows who've waded in here. I did a bit of searching for .52 rimfire and turned up the URL below. The specs (case length, bullet diameter and rim diameter) of the 52-70 it deals with closely approximate the chamber amd bore dimensions of my casting - so perhaps this is a cautious Eureka moment regarding what the carbine was chambered for.

International Ammunition Association {iaaforum.org} - View topic - What is this .50 Cal?? Please help

[Warwick]

It becomes much more interesting now that there is a possible issue of rarity. This is pure speculation of course, but that roller carbines went to places like China as Patrick states, triggers the idea that it could have been a bring-back - perhaps by someone from the small Australian contingent taking part in surpressing the Boxer Rebellion. Certainly whatever this unusual calibre is, it doesn't sound likely to have been part of an 'official' = government contract/shipment for local use here, but who knows? And yes, I've signed up for the book, but it will take a fortnight or so to get here. And tonight I order a centre-fire block casting from The Gun Shoppe Inc, in Jones OK to get me started. But you know I've never heard of a 32 Gauge shotgun down here, so it will be interesting to see whether my local gunshop carries them or indeed knows of them. Watch this space.

[Warwick]

Patrick I don't have a case I can measure for head diameter. The only dimensions I have are taken from the chamber cast and I attached those in an earlier post. I'll try re-attaching them here - it's the best I can do for now.

[Patrick Chadwick]

Sorry to be so slow on the uptake! Got it now.

As to the interpretation of your chamber cast: I do not think that a cartridge with a case anything like 1.480" long will fit, because this would mean that the bullet was entirely within the throat.

But if you look at these old rimfire cartridges you will see that the bullet is often just as wide as the case. They were heeled bullets, rather like modern .22 long rifle bullets (dismantle a .22 cartridge and you will see what I mean). So the cylindrical portion of the bullet would have to be chambered back in the full width section, with just the nose of the bullet entering the rather steep throat. The case would therefore be somewhat shorter than the distance to the throat - by about 1/2 a calibre, I reckon.

The thread you linked is especially interesting, as it suggests that the 52-70 was a "Quick-fix" to make rifles and carbines with worn-out .50 bores usable again. Sounds very plausible. And as you can see, when trimmed to an appropriate length, the Cal. 32 case I recommended will indeed be a neat fit in the chamber.

Regardless of the original chambering, without having heeled bullets you will need to "cut and fit" the case length and bullet seating depth to suit your carbine. And since the non-heeled bullet cannot be as wide as the groove diameter because it is sitting inside the case, you must use pure lead bullets (maybe with 2-3 % tin) so that they can obturate to fit the bore. Hence the suggestion to use muzzle-loader minié bullets. After all, from the ballistics point of view, firearms of that vintage are not much different to contemporary muzzle-loaders.

Whether or not your gunshop has heard of Cal. 32 shotshells, the brass shotshells are made by Magtech. So look for a supplier of Magtech brass shotshells.

Since the walls are thinner (and the cases cheaper!) than any rifle shell of comparable diameter, they will enable you to get closer to the groove diameter in your bullet selection than a thicker-walled rifle case would.

Follow the recipe I outlined before:

"Bullet weight would be around 400 gn. With BP, the bullet should be seated to be about 1mm (1/32") off the lands. Go much closer with BP and you are likely to have chambering problems with a dirty bore/throat. Pick case length accordingly, for adequate seating of the bullet.
Powder charge = fill it with Swiss No. 4 (1-1/2 Fg) with an overpowder wad."

It will work. Quite possibly very well indeed.

So get a .54/.535 minié mold as well. If you are in a hurry and don't want to spend the money on a mold, .54/.535 miniés are made by Pedersoli and should be available from an ML-supplier. Heck, in desperation you can even push a .535 or .54 roundball into the case! Several people have done that as a quick fix for Sniders, pushing a .580/.585 roundball into a Cal. 24 plasic shotshell cut to length. And it seems to work quite satisfactorily up to about 50 meters!

[Patrick Chadwick]

Just to show how intriguing the field of RBs is:

A few days ago I purchased a slightly odd-looking RB online. The seller knew next to nothing about it, and there were only fuzzy pics to go by. I thought Bubba might have got at it, as the fixing of the block and hammer pins is unusual. Belgian knockoff maybe? Anyway, I got it for a wallhanger price, and it should soon be on its way to my local dealer.

- And then, looking through the book to find your carbine, I saw it!

OMG, I think I've bought a Whitney !!!

[jmoore]

Just to show how intriguing the field of RBs is:

A few days ago I purchased a slightly odd-looking RB online. The seller knew next to nothing about it, and there were only fuzzy pics to go by. I thought Bubba might have got at it, as the fixing of the block and hammer pins is unusual. Belgian knockoff maybe? Anyway, I got it for a wallhanger price, and it should soon be on its way to my local dealer.

- And then, looking through the book to find your carbine, I saw it!

OMG, I think I've bought a Whitney !!!

Whitneyville? Early split breech or similar? Had hands on a pile of odd RBs a few years back, but didn't get any or even photos. But there sure were some strange variations!

[Patrick Chadwick]

Seems to be a Style I (Layman's usage) Whitney** RB rifle in .43 (stamp on barrel), presumably .43 Spanish, similar to the Mexican RB shown on P.190 of the Layman book. Wood has been replaced by sporting style, but decently. Seller claims visible rifling, whatever that means*. Receiver has decorative curved edge to top sides. So either from new as sporting rifle, or Bubba-ed. Price was OK - a bare 3-figures, worth it for the system. I just hope the barrel is usable. Photos when possible. Wish me luck!

* "visible rifling", in my experience, means anything from "as new after cleaning" down to "next stop - hacksaw". Which is why one should never pay more than a wallhanger price for online oldies!

**Whitney-Laidley?, not sure if Type I, photo too unclear.