The.45 Colt...............

[Driftwood Johnson]

Could any of the fellows with older 45 Colt cases measure the wall thickness and compare it to more modern 45 Colt cases? When I was first shooting 45's in the 80's, some of the cases seemed thinner walled, and older cases in particular did. When loading them up to higher levels become popular, it seems the factories began to make the case walls thicker. I'm curious if measurements bear out my recollections.

How would early 1900's commercial cases, pre-WWII cases, and 1950's cases compare in wall thickness with todays cases?

Howdy

Funny you should ask. I have a few old 45 Colt Balloon Head cases made by the Dominion Cartridge Company. The Dominion Cartridge Company was a Canadian outfit that made ammunition from roughly 1885 until 1945.

For those who do not know what a Balloon Head case is, here is a photo comparing an old UMC Balloon Head 44-40 case to a modern Solid Head 44-40 case made by Starline. Notice the construction of the case head at the primer pocket. Modern Solid Head brass completely encases the primer pocket in solid brass, whereas the primer pocket on a Balloon Head case pokes up into the interior of the case. The idea would be the same with 45 Colt.



I also have a box of old Remington Balloon Head brass but it has all been flared and it is difficult to get an accurate reading on the brass thickness at the case mouth. I bought the box of Balloon Head brass because I wanted to see how much more powder would fit into one of the old Balloon Head cases than in a modern standard Solid Head case. The standard figure for how much Black Powder would fit into a 45 Colt case is usually given as 40 grains. However, modern brass has less case capacity than the old Balloon Head brass. I generally find that, depending on the brand of powder because they do not all weigh the same, I can only get about 33-35 grains of FFg Black Powder into a modern Solid Head 45 Colt case under a 250 grain bullet. This is because I only compress the powder a modest amount, about 1/16" - 1/8". Just about the only way to get 40 grains of Black Powder into a modern case is to use a compression die to compress the powder a bit more. For my purposes, 33 -35 grains of FFg provides plenty of buck and roar.

Notice that Balloon Head brass cross section is not the same as Benet primed brass.

Anyhoo, to answer the question, the Old Dominion cases measure about .008 thick at the case mouth. Modern 45 Colt brass tends to run around .012 thick at the case mouth. No, I am not going to section one to find out how thick it is all the way down.

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Regarding rim diameter; SAAMI spec for the rim of modern 45 Colt brass is .512 +0/-.012. Most modern stuff tends to run around .510 or so. I don't find an actual SAAMI spec for 45 Schofield, but according to my Speer Reloading Manual, 13th edition, nominal rim diameter for 45 Schofield is .520. No tolerance is given. All the Schofield brass I have is modern stuff made by Starline. It tends to run .519 - .520 in diameter at the rim. Sorry, no antique Schofield ammo in my collection as of yet.

Modern 45 Schofield brass chambers fine in my Colts, but there is a slight problem with it in a couple of older Ruger Vaqueros. Because the ratchet teeth geometry of a Ruger is different, there is not quite enough clearance on one chamber of each of two 'old' Vaqueros to seat a Schofield round. I took care of that with a few swipes of a file on one Vaquero, the other one is waiting for the treatment.

Here is a photo of a bunch of old 45 Colt rounds in my little collection. They were made by various manufacturers, including UMC (Union Metallic Cartridge Company), WRAC (Winchester Repeating Arms Company), Western, WRA, and one is unmarked. Rim diameters tend to run from .505 to .510 with this ammo.

Except the one on the far right. I believe it is one of the 1909 variants we have been talking about. This round is headstamped F A 12 13, which means it was made at the government Frankford Armory in December of 1913. The rim diameter of this round is whopping .538. It will chamber in a Colt SAA, however there is not enough room for another rim like it to be chambered next to it. However it chambers fine in my old Colt New Service, the revolver it was developed for.




Manufacturing tolerances must have been a bit loose on this Benet primed 45 Colt ammo. Perhaps because of the folded rim construction. Most of the rims seem to run around .505 in diameter, but a couple are a bit lopsided and are down around .501 in diameter. Still, it does not really matter. The 45 Colt cartridge was designed to be poked out from the inside with an ejector rod, not grabbed on the outside by an extractor.

 

[Malamute]

Anyhoo, to answer the question, the Old Dominion cases measure about .008 thick at the case mouth. Modern 45 Colt brass tends to run around .012 thick at the case mouth. No, I am not going to section one to find out how thick it is all the way down.

Great post Mr Johnson.

Thanks for the information. No need to section a case, the mouth is the main thing I was curious about.

I have a Miroku 92 in 45 Colt. They are a bit loose in chamber dimensions, as seems common with lever actions. It soots up modern cases, even with some fairly stout loads (22 grs 2400 w/225 gr Speer JHP). I've experienced cases sooting up in Ruger and Colt revolvers also. The 44 spl also seems to do it, the cases for them have been relatively heavy for the time I've been shooting them, but some older cases I came across seem a bit thinner (REM-UMC and some older WRA Co headstamp).

On a side note, I live in the northern Rockies, in a state known for plenty of history and wild country. I took a two track road in sagebrush country one day and stopped to shoot my Colt NM 45 auto. After shooting 100 rds, I picked up brass. I ended up losing several, but I inherited an old 45 Colt case. Interesting that I stopped in exactly the same spot as someone so many years ago. I showed it to a local guy that was known for his historical knowledge, including gun stuff. He said he thought that the headstamp on the case I found wasnt used past about the first World War.

I've found other cases, but no inside primed ones. A lady visiting me once found a fired inside primed 45-70 case in my yard though.

I like the Lubaloy round in your lineup. I aquired a full box of 45 Colt Lubaloy rounds in the old yellow Western box with red X on it.

 

[Driftwood Johnson]

Your experience with sooty chambers in a rifle chambered for 45 Colt is very typical. Well known in the CAS world. Those thick modern cases do not swell up as well to seal the chamber as some older ammo did. But then of course, 45 Colt being chambered in a rifle is a completely new phenomenon, only going back a few years, probably to the 1980s with the rise of CAS in popularity.

I believe I made a comment early on about the narrow rims of the early 45 Colt ammo not being very suitable for the extractor claw of a rifle. It was not until very recently with modern solid head ammo and a substantial rim that it became feasible to chamber 45 Colt in a rifle.

44-40 on the other hand, was designed from the ground up as a rifle round. Always had a substantial rim for a rifle extractor to grab, going back all the way to 1873. And those of us who shoot 44-40 loaded with Black Powder in a rifle are very partial to the round. Case mouth thickness tends to be a skimpy .007 with modern 44-40 brass. That means the case expands and seals the chamber very well even under the light pressure developed by Black Powder. When my 44-40 cases eject they are almost as clean on the outside as when they went into the chamber. All the fouling stays in the bore, where it belongs.

P.S. By the way, how do you like that Miroku? I understand they are very nice rifles, very well made.

 

[Dframe]

You've come through again. Thanks for a fascinating post Bob