The .45 Auto Rim is now obsolete?

Oh yeah, he chuckled a bit when I told him I had heard the .45 Special is intended only for SA revolvers.
 
That's Ok because no one said that. The question is will this 45 Special fire from a da revolver chambered in 45 acp. I'm not so sure of that because of the case rim being the same as the 45 Colt.

By the way Starline began making this brass since in 2013 when they made it for Speedbump Stockworks. It's been sold as the ".45 Cowboy" and the 45 Special.

The Cowboy .45 Special is a case that is optimized for use with light loads in .45 Colt caliber revolvers for Cowboy Action Shooting. Light loads with excessive airspace are a recipe for case splits and erratic function. By using the Cowboy .45 Special case, with its .45 Colt rim and .45 Auto length, the problem no longer exists. While many claim that .45 Auto load data can be used in this caliber, it is important to realize the limitations of the firearm it is chambered in and only use loads that fall within the pressure range of that firearm. Generally these can be loaded using .45 Colt dies and a modified (shortened) crimp die, or .45 Auto Rim roll crimp die.
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tipoc
 
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The question is will this 45 Special fire from a da revolver chambered in 45 acp. I'm not so sure of that because of the case rim being the same as the 45 Colt.
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I would say, yes it will.

I have a 625JM revolver and I am a HUGE 45 fanboy. I shoot primarily 45 Auto Rim due to the fact that moon clips are a pain in the behind to load up. And unless you are using the gun for self defense or competition, what's the rush? I do use the clips from time to time but, as mentioned by Driftwood, they aren't needed at all in the 45 ACP revolvers since they head space on the case neck and not the rim like a typical revolver cartridge does.

That is why I think the 45 Cowboy WILL work in the 625 revolver (if taper crimped) and it would probably engage the ejector star too. I still like the 45 AR brass better though since I prefer to roll crimp revolver ammo.

One caution about this brass is that many 45 Colt revolvers cannot be loaded to 45 ACP pressures safely and so you SHOULD NOT use 45 ACP load data in these firearms.

Take note.
 
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When I first started loading .45 Colt, I immediately noticed that the volume of the case occupied by powder was extremely small.
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From what I've read, this is the reason they came up with TRAIL BOSS powder. Trail Boss is light and "fluffy" has a lot of bulk for its weight. It is made to take up the "air space" in the old blackpowder cases (.45 Colt, .44-40, .38-40 etc.) and deliver full (standard black powder) velocities.

No need for a special short case if you use Trail Boss.

Just talked to Hunter at Starline, their tech guy. Three points:

a) the .45 Special case is the same as the .45 ACP and .45 AR, except for a different head (i.e., rim).
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Is it possible that the tech guy at Starline was only talking about the case LENGTH when he said this?? I think he was, because of the (b) and (c) statements.

It would be very odd for a company to make a case, INTENDED to be used in .45 Colt chambers (just shorter length than the .45 Colt case), and make the body dimensions (diameter & length) identical to the .45ACP, "just with a rim".

length, sure, but NOT width. Some people seem to think the .45Colt/.45ACP thing works just like the .357 Mag/.38 Special or .44 Mag/.44 Special does, but they DON'T. With the Mag/Special interchangeability, it works because the cases are the same dimensions in all aspects, EXCEPT for length.

This is not the "case" with .45 Colt / .45ACP & .45Auto Rim.

Again, I point to the specs, the .45ACP/AR case is 0.007" smaller than the .45 Colt at the case mouth. The ACP is 0.004" smaller than the Colt case at the case head, And the ACP case is 0.480" RIM diameter, which equals the .45 Colt case MOUTH diameter.

SO, why would Starline (or anyone else) make a short (ACP length) case to fit a .45 Colt chamber with the undersize, and tapered dimensions of the ACP brass???? Makes no sense. SO, I think the "tech guy" at Starline must have been referring only to the case length, not all of the dimensions when he said it was the same as the ACP, but with a rim.

Generally these can be loaded using .45 Colt dies and a modified (shortened) crimp die, or .45 Auto Rim roll crimp die.
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Here's a point to be aware of, if you buy the short Cowboy brass, you will need a special die to crimp it. Standard .45 Colt dies will load it, they have enough adjustment for that, but they can't crimp it, because the seater die body is too long to allow the crimp shoulder to contact the short case mouth.

SO, either cut off enough of the bottom of a .45 Colt seater die to compensate for the short Cowboy case, OR use a .45ACP die, which might not have a roll crimp in it, depending on the age of the die.

The taper crimp found in modern ACP dies might be fine using the light loads the short Cowboy brass is intended for. Only field testing in your gun with your loads and your crimp amount will tell.

A roll crimp WILL work fine, but today I don't think its built into ACP seaters like it once was. I don't know for sure.

I do know that Lyman .45ACP die sets from the 70s (and older) were made to load ACP and AR, and have a roll crimp built into the seater die for the AR. Not sure what other die makers did.
 
I can tell you that I use the same bullets across the three calibers: 45 ACP, Auto Rim, and 45 Colt without issues.

Modern 45 Colt is using the same .451/.452 bullets as the 45 ACP and Auto Rim so necks are the same across the three rounds IF using a modern 45 Colt with the .451 Rifling such as my Ruger original Vaquero and modern brass. I use Starline across the board.

I have Redding 45 Auto Rim Profile Crimp and they are producing one already for the 45 Cowboy but I am sure it's the very same die.

It would be fine and maybe even preferable to use a taper crimp in the 45 Cowboy depending on your bullet selection.

No need to modify any dies, unless you want too.
 
Most revolvers today can't use the Auto Rim because the rim is too thick, so .45 ACP revolvers are stuck either using moon clips or ejecting brass with a rod.

I've seen a video where somebody had to trim the case of the Cowboy Special brass to fully chamber in a .45 ACP Blackhawk cylinder. Once the brass was trimmed, it worked fine in the Blackhawk.

For other revolvers... Idk. I think it's something we'll have to test in various .45 ACP revolvers to see if this brass will work. If it does, it does make the .45 AR obsolete for everything except the old M1917 because this brass can work in any .45 Colt revolver.
 
TruthTellers, please explain:

Most revolvers today can't use the Auto Rim because the rim is too thick, so .45 ACP revolvers are stuck either using moon clips or ejecting brass with a rod.
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If the revolver can take the .45 ACP with clips, why can't it take .45 AR?

I've had several M-1917 Colts and S&W guns, plus the Models 25 and 625 and all took .45 ACP and AR with ease.

Bob Wright
 
The same with me. In my experience, and it was only a few weeks ago, the Auto Rim works in 45 acp revolvers.

tipoc
 
44 AMP, you're probably right in that the dimensions of this case are based on the .45 Colt case's SAAMI specs. I think what he was more specifically referring to was the tapering of the inside wall of the case. As a matter of fact, I do remember him mentioning just that point.

But he was also VERY clear on another point, these cases are tested to the same pressures levels as the .45 ACP cases. Of course, that doesn't mean your revolver can handle those pressures.
 
New ammo for this round from American Cowboy Ammo

http://acammo.com/index.php/products

American Cowboy Ammo is pleased to introduce the New ACA Cowboy .45 Special. This new load has a very low recoil, a reloadable brass case, and it features a 180 grain, round nose, flat point bullet that is ideal for improving your shooting velocity.

ACA Cowboy .45 Special

180 Grain Round Nose Flat Point

New Proprietary Brass Case

Reloadable

Muzzle Velocity: 475 fps

Perfect for Target Shooting, Training, Competition and Plinking
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This is useful regarding pressures and reloading.

http://www.dakotaskipper.net/ebay/cowboy45special.pdf


tipoc
 
Bob Wright said:
TruthTellers, please explain:



If the revolver can take the .45 ACP with clips, why can't it take .45 AR?

I've had several M-1917 Colts and S&W guns, plus the Models 25 and 625 and all took .45 ACP and AR with ease.

Bob Wright
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I can't speak for every .45 ACP revolver, but most revolvers that I'm personally interested in can't use .45 AR.

I have no interest in the S&W 25 and 625, so I was unaware that they worked with them.
 
First of all, let me say, the premise that one cartridge case is obsolete because a new cartridge case is available for an entirely different cartridge is somewhat silly. Second, the idea that the new case is anything other than a shorter version of the .45 Colt case is equally silly. Tested to the pressure levels of the .45 ACP? That is only 23k psi when talking about .45 ACP +P pressure level. When .45 Colt brass are regularly subjected to Ruger pressure levels that exceed 30K+ psi, why would testing to 23K psi tell us anything? Does anyone seriously think that Starline in addition to shortening a .45 Colt case to create the .45 Special case, also decided to "weaken" it?

Don
 
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Guys

The 45CS WILL NOT work in revolvers chambered for 45ACP. Just about any revolver chambered for 45ACP will have the extra .030 of headspace at the rear of the cylinder for 45ACP moon clips. That is why the 45 Auto Rim has a rim thickness of .090. 45 Colt, 45 Schofield, and 45 Cowboy Special all have a rim thickness of .060. If you place a cartridge with a .060 rim thickness in a revolver with the extra .030 of headspace, the cartridge will slop back and forth. When the hammer falls, if the cartridge is all the way forward, the firing pin will not protrude enough to reliably ignite the primer. If it does ignite, the round will recoil back an extra .030 before striking the recoil shield, which is not going to be good for the revolver. Trust me on this, I just tried chambering a 45CS in a S&W Model 1917 and a S&W Model 1955 Target, both chambered for 45ACP.

Yes, the 45CS was developed primarily for Cowboy Action Shooting, so many shooters believe it is only for Single Action revolvers. That is incorrect, it can be fired in any revolver chambered for 45 Colt.

Yes, that is why Trail Boss was developed, to reduce the extra empty space in large capacity Black Powder cartridges. However, many shooters believe Trail Boss is a Black Powder substitute. It is not, it is a modern Smokeless powder developing Smokeless pressures.
 
The title of this thread should get a prize for most misleading thread title. It's cool that the 45 Special is now available for CAS shooters who want to make extra light loads to shoot in their 45 Colts.

Since the 45 Auto Rim is used in completely different guns and the two are not interchangeable, the introduction of the 45 Special doesn't make the 45 AR any more obsolete than it already was.
 
Well I was poking around and found some things out. Also that I was wrong on a thing or two.

Remember this is a round most of us know little about so sweeping claims can lead a fella like me to say "I was off on that". It's better to speak from actual experience with this round.

1. The 45 CS (that's Cowboy Special) cartridge was developed in about 2005 by Adirondack Jack out of N.Y. for use in shooting lighter loads of the 45 Colt round in Cowboy action shooting where speed is needed to compete. A wildcat round. From 2005 to the present the brass has been made by Starline. It's been called the 45 Cowboy, or 45 Special but it's all the same round. Essentially it's a 45 Colt case cut down to the length of the 45 acp. It's not a new round.

Best source for some basic info is here...

https://forum.cartridgecollectors.org/t/45-cowboy-special/16974

2. Left to right below, 45 acp, 45 AR and 45 Colt



Note the width of the rim and the diameter of the rims.

45 AR rim dia. will vary from .512-.516, thickness or rim is from .080 to .089
this is the actual measurements of the cases above and the specs from the books.

45 Colt rim diameter .507-.512 and the thickness .055 to .060

I don't have a case for the 45 CS but the dimensions of the rim should be identical to the 45 Colt. The IAA places it identical to the 45 Colt except for the OAL.

The diameter of the 45 AR rim is wider than that of the 45 Colt by a few thousands. The rim is thicker by almost .030"

3. The 45 Colt CS will chamber and fire from any revolver chambered in 45 Colt, obviously. But what about wheelguns chambered in 45 acp?

Any older da revolvers like the Colt and S&W M1917 and the M25, all in 45 acp that were meant for the use of 6 round clips the 45 AR will chamber and thus the 45 CS should chamber. Remember, these guns could also fire the 45 acp without the clips and were intended to. So the rearward movement of the cases after firing was not a critical issue.

But, there is a newer batch of 45 acp 5 shot da revolvers, some with recessed faces, where the 45 AR will not fit due to the cylinder being smaller. These guns were not built with the 45 AR in mind. It's possible in some that the 45CS will also not fit but one has to see about that, case by case. The rim of the 45CS is close to the same diameter as the 45 AR.

I've also read complaints about the old model Blackhawk with switch 45 cylinders as well on the Ruger forum. In single action revolvers with a 45 acp cylinder the rimless 45 acp rests on the case mouth.

4. Pressure. The 45 CS should be capable of working at 45 acp pressures. The same is true for the 45 Colt by the way. If the guns are not older guns, older meaning pre-smokeless powder, or built for black powder only. But there are debates about this over the years. So build up slowly.

tipoc
 
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The 45CS WILL NOT work in revolvers chambered for 45ACP. Just about any revolver chambered for 45ACP will have the extra .030 of headspace at the rear of the cylinder for 45ACP moon clips. That is why the 45 Auto Rim has a rim thickness of .090. 45 Colt, 45 Schofield, and 45 Cowboy Special all have a rim thickness of .060. If you place a cartridge with a .060 rim thickness in a revolver with the extra .030 of headspace, the cartridge will slop back and forth. When the hammer falls, if the cartridge is all the way forward, the firing pin will not protrude enough to reliably ignite the primer. If it does ignite, the round will recoil back an extra .030 before striking the recoil shield, which is not going to be good for the revolver. Trust me on this, I just tried chambering a 45CS in a S&W Model 1917 and a S&W Model 1955 Target, both chambered for 45ACP.
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Driftwood, do you have a 625? The reason I am thinking it would work fine is in my 625JM I can load 45 ACP with or without the clips and they headspace correctly. I don't have any 45 Cowboy, and probably won't as I use Trail Boss and have mucho 45 Colt brass, but it looks as though the COAL is the same with 45 Cowboy and if so, it should chamber and fire reliably in a 625.

I normally shoot the 45 Auto Rim in my 625 but it shoots the Auto Rim and the ACP with the same boring reliability. (After having sent it back to the factory, but that's a story for another thread.)

More choices are always good.

Also, Staline says that the 45 Colt brass they sell is tested to the same pressure as their 44 Magnum brass: 40000 psi

Now I might have to order a bag of brass to play with.....
 
all in 45 acp that were meant for the use of 6 round clips the 45 AR will chamber and thus the 45 CS should chamber.
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Two small points with this statement, first I believe (will have to check to be certain, but I believe) that the 1917s and similar guns were used with the 3 round half moon clips early on, and the 6 rnd full moon clips didn't come out till much later.

Second, I just did some checking with some .45 Colt rounds and a Ruger Blackhawk .45acp cylinder.

The only reason the .45 Colt fits in the chamber is that the ammo is made SMALLER than the specs. I will assume the .45 Special is the same way.

The specs (and yes, they are the max allowed) show .45 Colt at 0.480" at the case mouth, which should NOT fit in a .45ACP chamber, however, the actual rounds I measured go only 0.476 at the case mouth, which is the same as the case head max spec for the .45acp.

SO, between ammo made slightly undersize (and I will assume the .45 Special is the same as the .45 Colt in this) and chambers being at least large enough for the max size ACP case, then the rounds fit (except for the length).

SO, it is POSSIBLE that a .45 Special, at the large end of the tolerance range and a .45ACP chamber at the small end of the range might not work together.
 
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