Reloading questions for 0.50 Rimfire Remington Rolling Block Carbine

I just bought sight unseen a Remington RB carbine. It was advertised as.50 calibre and ‘good for its age’. On first examination it looked pretty grim but while this gun has I think, lost its historical/collector value, it does have potential as a shooter. I want to shoot it but here’s the rub. In finding or creating a cartridge which will shoot – there are two main issues. First, it has a rim-fire block, and second, while it is notionally 0.50 calibre, (i) the bore slug gives it a groove diameter of 0.534 and a diameter of 0.517 for the lands and the chamber cast shows (Ii) the original cartridge is straight walled and possibly as long as 1.5 inches from its base to the commencement of the throat at the chamber, and (iiI) at 0.660, the rim diameter is exactly the same as that for the 50/70 Government cartridge. See attachment.

I can identify no rimfire cartridge (Spencer, Joslyn etc.) whose specs may have been a match for this chamber and upon which I could base the conversion of a centre-fire case to suit, although the 56/56 Spencer comes closest. Because of the suitability of the common rim diameter to the 50/70, I then thought the 50/45 or 50/55 centre fire cases which the 50/70 is based on might have specs which match instead. But they do not – for the simple reason their bullet diameters are about 0.515 – projectiles which are way too small for the bore on this gun.

The best I have been able to come up with for the moment is to paper patch (using .008’ paper) the 0.500’ 400 grain bullet I use in the 12.17 roller, to bring it up to 0.532 diameter. This seems to fit pretty well, although whether the patched bullet would work in a somewhat rough bore is a question for the future. I used this patched bullet to slug the bore and it seemingly was a very good fit. Somewhat hard to drive down the bore, but it picked up the rifling completely and afterwards measured the same groove and land diameters of the casting. So this is one possibility. However, if I was to base the proposed cartridge on a shortened 50/70 case and this bullet (patched or plain), the case would probably have to be substantially shorter than 1.48 inches if it was to have a wide enough throat to accept the bullet. That in turn would present the question of how much powder such a shortened case could carry under a bullet of that length and diameter. Another possibility is to do a little reaming to have the chamber extended to take a longer case. These are considerations I have to work on some more. But any assistance in getting me along the road to getting this thing shooting (the areas of uncertainty I have are captured in the questions below) would be greatly appreciated.

(i) What is the original rimfire cartridge this gun was chambered for – and does anybody have any specs for it in terms of physical dimension s, bullet weight and shape and powder charge,
(ii) Has anybody successfully prepared a cartridge for the 0.50 calibre rimfire,
(iii) Other than the 50/70, does anybody know of a donor case suitable for conversion,
(iv) Is there a mold (mould?) of suitable bullet shape, weight and diameter out there I might be able to get my hands on,
(v) I will need to convert the block from rim to centre-fire. Do-able of course but is there any intrinsic value of this rimfire gun which suggests it would be better to obtain a centre fire block and using it instead,
(vi) Has anybody any experience with the block castings available from The Rifle Shoppe – how much fettling is involved in getting them to fit and work,
(vii) Does anybody out there know where I can get a used #1 centre-fire block for a #1 Roller?

My own opinion is that to modify the roller to centerfire would be expensive unless a replacement breechblock could be found. bullets and brass is another consideration and I would imagine somewhat expensive as well. There is probably european brass that might be modified to work. In the end you will wind up with a rifle that has been modified from the original. I would just keep it as is for historical purposes. I have a roller in .50 carbine that is centerfire with the Navy anchor on the barrel. Fun to shoot no doubt. It uses 50-70 brass shortened and they work well in the 50-70 trapdoor I have as well. What I have found with rimfire rollers is they are low pressure affairs usually loaded with 1F powder.

Are you sitting tight? I don't want you to fall off your chair laughing!

It seems to be a Caliber .52 chambering, not a Caliber .50!

The ONLY candidates I can find are on P136-7 of "The American Cartridge" by Charles Suydam.
Group 61:
No. 1 Sharp & Hankins Carbine: rim/ bullet/OAL/case .633/.543/1.676/1.133
No. 2 Sharp & Hankins Rifle .640/.538/1.756/1.153
No. 3 Sharp & Hankins Rifle .645/.549/1.771/1.158
No. 4 and 5: OAL too long

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.


P.S: Cancel the Sharp & Hankins option. Layman has no mention of this calibre being used in RBs

- or, just possibly, a 54 Ballard (Old Rifle or Carbine) !!! (see P.138 of the book)
- or, just possibly, a 56-52 Spencer!!!
- or even a 56-56 Spencer!!!


All these are so close together, and the known specimens in the book show such variations, that some dimensions overlap and very precise measurement of the chamber cast is required.

In particular, please measure the HEAD diameter from your chamber cast. This is a vital dimension for narrowing the range of candidates for the original chambering, AND for selecting a donor case type.

A 32 cal brass shotgun case is probably going to be your best bet for a donor case for any of the above possibilities. Get one and see how it fits!

I admit to having had a bit of a laugh at the idea that this darned thing may have been deliberately chambered in a damfool calibre so as to deliberately get up my nose 150 years later. But thanks to both of you for your input and efforts. In truth, the gun has no collector value. It has no markings anywhere other than a glimpse of a two-line Remington address on the upper tang. Oh yes, there is a 'u' on the barrel band. It is not a cut down rifle, but it definitely started life as a rifle action - it still has the threaded plate for the cleaning rod in front. Someone in its history badly blued all its metal surfaces, so with its originality gone, I have no hesitation in doing further mods to make it a shooter. Bubba made the oversight of forgetting to sand its wood which are in pretty good shape. So I've removed all of the blue using commercial rust remover to render it completely in the white - a great improvement, and a couple of divots in the stock I have repaired with old walnut. It is looking OK now. I'll see if anybody else can offer any more assistance with shooting it with the bore as it is, but if not, it is likely to be resleeved in 50/55 or 45/70.

The U on the barrel band strongly suggests a one-time military gun. The U was to be readable when the rifle was racked, i.e. it shows that the barrel band is the correct way round.

Don't go to all the expense of resleeving the barrel. Please read my posts on the Pickelgewehr (search) to see that one can, with a bit of luck and elbow-grease, bring back some barrels from the dead. If the bore shows that it is worth shooting, cut 32-gauge shotgun shells to the length as determined above, and use .54 cal minie bullets for muzzle-loading rifles! You will, of course, have to convert the block to centerfire, or find a replacement, but that is going to be easier than making rimfire cases! (Been there, done that - for my rimfire Peabody - it's a PITA).

Patrick thanks for that. Having looked at Your work on the other gun and your recommendation that I hold off resleeving mine, I've attached a few photos, both of the gun and its bore so you can see what I'm dealing with. The bore in mine in fact, is better in real life than the photos suggest. It actually has pretty fair rifling and some shine along its length as well as a few pits and roughnss - but certainly enough of a bore remaining to justify trying to make it work at the calibre it is. I'll cast about for some .32 gauge shotshells and the minnie you suggest. But the other idea I'm running with is to first get it centrefired and then fireform some shortened 50/70 cases and shave them back enough for the expanded case to accept the patched bullets I'll make. If that works, it is game on. If not, then the .32 cases.

The distance between the bae of the chambered patched bullet and the breech entrance is about 0.880". Add that to the seating depth of the same bullet of 0.457" and i have an indicative fireformed case length to accept that bullet (or your 0.54 minnies) as well as chamber properly, of about 1.4 inches. In point of fact there's little to be gained in expending more cash than the thing is worth just to get it shooting in another calibre, so it is a case of do or die with the existing calibre (whatever that is).

"...while this gun has I think, lost its historical/collector value, it does have potential as a shooter..."

Hey! I disagree! That ain't no Bubba job, that looks like an original military RB carbine. Historically interesting indeed and, yes, it ought to be shootable.


Before you do ANYTHING irreversible to that rifle, I think you ought to (no, make that MUST) get hold of "Remington Rolling Block Military Rifles of the World" by George Layman and read up on RBs. Rbs WERE made in 50-52 (Cuba and Puerto Rico), 56-52 (Peru) and 56-50 (Mexico) rimfire chamberings. It has NOT been Bubba-ed. In fact, because it is a rimfire, it has probably had a long, long rest. Schuyler Hartley & Graham appear to have shipped RBs, both rifles and carbines, all over the place, including Korea and China, and just about everywhere south of the border!

Patrick I'm not going to change anything on the thing - and thanks for your input. I've more or less abandoned the idea of resleeving or rebarrelling it, having discovered that the cost of doing so is pretty hard to justify. You correct me if I am wrong, but I assume the loss of its original finish with a reblue now removed, has turned something which was once collectable, into a presentable, shootable wall-hanger, nothing more. In any event, getting it to shoot is the end-game, to which end sourcing a centre-fire block and making up cartridges on the basis of what we have discussed is the strategy now. Let's see how things develop. BTW, what are the specs of the .32 shotgun case that give it application here?

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!!!

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...

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!

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

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.

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.

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 Swisshttps://www.milsurps.com/autolinker/images/link6.gif 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!

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 !!! :cheers:

Quote:

---

Originally Posted by 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 !!! :cheers:

---

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!

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.

Patrick, my work on the carbine is in suspension for now. Magtech has no 32 bore shotshells on its Australian website and importing the things would smother me in red tape with success by no means assured anyway. So I am back to the 50/70 case cutdown to suit the bullet seated further back and I have managed to get a cut down case to chamber. Next step is to ream/expand it to 0.534 so I am in proces of making up expander plugs. I've ordered a block casting from The Gun Shoppe, but I feel as though I am dealing with people on Mars - their phone has the same recorded message day after day - speaking to a human being has proven impossible thus far, meaning I don't know if the order is placed successfully. And until I have a working CF block - no investment in a mould.

"And until I have a working CF block - no investment in a mould."


Understandable. But you could at lest get the 54 minie bullets

http://www.davide-pedersoli.com/dist...australia.html


Importers and distributors
FORBES WHOLESALE PTY LTD.

P.O. Box 589 - 3095 - ELTHAM - VICTORIA
Telephone: 0061 39 439 6111
Fax: 0061 39 4397288
Email: forbes@forbesws.com.au

- I hope!

If you can't find .54 minies, look for .54 bullets for the percussion Sharps rifle.


In both case, you might have to fettle up a simple sizing die to squeeze the bullets down to the optimum size for your cases.

"So I am back to the 50/70 case cutdown to suit the bullet seated further back and I have managed to get a cut down case to chamber. Next step is to ream/expand it to 0.534 so I am in proces of making up expander plugs."

Before you carve up any cases and get involved with reaming, it is worthwhile taking that case and expanding or bell-mouthing it very slightly, until it shows a rubbing mark on the neck when you chamber it. This gives you a figure for the actual diameter of the chamber neck.

Take this value MINUS 0.002" as the maximum feasible neck diameter for a loaded cartridge.

According to this value, and the actual diameter of any bullets you may acquire, you will need to ream more or less - or maybe not at all, if you can get the thin-walled shotshells!

Inside neck reaming is a PITA, and I find it easier to expand the neck, set up the case in in the lathe with a tailstock-mounted pilot inside the neck, and turn down externally. Better still is to achieve a case/bullet/bore compromise where no turning is required!

Quote:

---

Originally Posted by 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.

---

It's arrived. And yes, it does indeed seem to be a Whitney-Laidley a.k.a. split-breech.
As for the rifling - "visible rifling" !! - make that "vestigial rifling" - it's there, intact, no gouges, but very, very thin.
Pictures when I have managed to get it to go bang!

Found your thread from 2015. If you are still stalled on this rifle, send a chamber cast to Rocky Mountain Cartridge co. in Cody, WY and have them turn some custom cases that are drilled to use a .22 CB blanl as a rimfire primer. I have seen these in RF Spencers, etc.

I am curious about the type of extractor present on your rimfire rolling-block and how the firing-pin is retracted. These points are probably useful in identifying its history.

FWIW - The U.S. Navy models used a coil spring to retract the firing-pin. The Navy breech blocks had a simple stud on the lower part of the block that caught the case rim for extraction.

Detailed photos of the block face and extractor might help ID this interesting Rolling-Block.