.43 Spanish vs .44/77 rim thickness

[NDuckhunter2]

Is there a difference in rim thickness between original rifles in .43 Spanish and .44/77 Remington? I have seen a couple different flavors of rim thickness stated for the .44/77, why is that? I’m hoping to use .43 Spanish cases in Lieu of .44/77 cases in an original rolling block #1 sporting rifle. I have another rifle that has .44/77 specs and use .43 Spanish brass with the neck expanded to take .446 bullets but it could also be an out of spec .43 Spanish, that gun is unmarked as to caliber. The new gun is marked .44 ctge S, I will chamber cast it but rim thickness is my real concern, I’m a little worried about the lack of .44/77 brass.

[desert deuce]

The one marked 44 ctge S Might want to chamber cast with rim to about 2 inches into the lands. Cast it, don't guess it.

[Luke]

FWIW, I have an Argentine rolling block that uses 43 spanish and .44-77 brass interchangeably, no rim problems at all. Both headstamps made by Jamison/Captech some years ago. My reading tells me that the .43 Spanish is the older chambering, and the .44-77 was developed from it.

[Luke]

To further expand: The parent case for both these rounds, indeed for much of Remington's catalog of that era, was the 42 Berdan. Remington simply tailored the bullet diameter and case length to customer demands.

[Luke]

Case manufacturing was in it's infancy back then. Specs varied between different countries, manufacturers, lots. Not unknown for troops to be issued new, correct headstamped ammo that would not chamber.

[TN Longhunter]

First, I agree, Cast it.
I did measure several brands I have on hand. These fit three Rollers in 44/77, one in .43 Spanish and one Sharps in 44/77. All originals

Brand Rim Marked
Jamison 0.078" 43 Spanish
RMTA 0.078" 44/77
Bell 0.078" Remington/Spanish Base
Bell 0.077" Remington/Spanish Base (different lot than above)
Bertrum 0.077 43 Spanish

Hope this helps

Don

[Clarence]

I had an Argentine .43 Spanish. I bought there standard (at that time 25-30 yrs ago) formed brass from Buffalo Arms. Case failures first firing. The rim recess was a great deal deeper than the rim thickness. I made a spacer to slide over the cartridge and effectively thicken the rim a s a test, and then I sent the brass back to Buffalo Arms; they bumped the rim thicker to match the chamber, and case life then was acceptable. I can get information on the rim thickness I ended up with if you are interested.

By the way, my chamber case indicated my rifle would take a case 2.625" long, so cutting the case to the nominal 2.25" would result in a very long freeborn. With bullets loaded into the longer cases, accuracy was very good.

Clarence

[desert deuce]

Yep, which points out the advisability of casting the chamber.

[NDuckhunter2]

Great info! I’ll try to get it cast this weekend. My military rifle is in very fine condition and assumed it was in .43 Spanish when I purchased it ( for a song and a dance). I decided to shoot it and chamber cast it and ended up being more of a .44/77 according to the specs I looked up but had used .43 Spanish cases just fine in it. The bore is most definitely .446. I actually size down .45 caliber slugs to fit the bore sometimes. Realizing that it may spec as a .44/77 but was probably shipped out as a .43 Spanish got me worried about rim thickness. It seems they are all very close and will be able to make .43 Spanish casings work regardless. Also Remington .44/77’s look like they have a shorter neck than sharps .44/77 shells, are they not the same specs?

[NDuckhunter2]

I chamber cast the gun, the rim is .085 thick according to the casting. My .43 Spanish cases fit in there fine but leave a little too much head space so the primers popped out a bit on firing, which is funny I figured it would blow the shoulder out and keep the primers flush. I fired 3 full bore loads out of it and all three popped the primers out a smidge. The bore measured .455 so will just use my .45 bullets and swage them down. The .446 bullets I fired leaded the bore horribly due to being under sized and the bore having some pitting but it’s actually pretty nice overall. The set trigger is not working, it is missing the rough and ready sight, and the front blade which appears to be ivory has mostly broken off. I did find a previous owners name engraved on the underside of the barrel, it had two initials and Overton in cursive engraved on it. I can’t wait to take it all the way down and see if there aren’t any more markings under the wood. It is a local North Dakota gun so who knows what kind of use it had.

[NDuckhunter2]

The engraving on the barrel is E.B. Overton after a closer look.

[bobw]

Just for kicks wrap some of those .446 bullets with a patch and try again. Nothing to lose. Bobw

[Clarence]

Nduck,

The rim thickness is similar to the one I had. With black powder loads, I began getting case stretching and case failures on the first firing. When I made a spacer washer to slide over the case to increase effective rim thickness, the problem stopped and I had good case life. A work-around until I could get cases from Buffalo Arms with the proper rim thickness (not sure they still make them because of the scarcity of .348 brass they used to form the cases).

Measure the case stretch-that will tell you whether you have the same problem I had.

My earlier post mentioned a longer case length-I looked in my records and found the case length I settled on was 2.555".

Clarence

[Clarence]

My groove diameter was the correct 0.439".

Clarence

[Don McDowell]

If you fireform the cases and then don’t do any resizing other than the neck thin rims won’t matter as the case will be headspacing on the shoulder