The .45 Auto Rim in a .45 Colt revolver

[cfullgraf]

Get a BMT Equipped mooner/demooner tool. A bit pricey but takes all the effort and angst out of loading, using, and unloading moon clips.

http://bmtequipped.com/index.php

I also load up a bunch of moon clips in advance, but store them in a Berry Mfg plastic 30 cal ammo can.

After returning from the range, I usually unload the moon clips and immediately refill them since you use the same tool. No handling of the moon clip itself in between.

I have 45 ACP, 9x19 and 38 Special revolvers that use moon clips.

 

[Driftwood Johnson]

Howdy

I guess it's nice to know the OP found magazine articles verifying what I said in the first place.

Regarding shooting a 45 ACP revolver without moon clips. I do it all the time. I for one, cannot be bothered messing around with moon clips. Just don't care. That's why I like the 45 Auto Rim round. The whole point of the Auto Rim round was to give the extractor star something to grab. That's why moon clips were invented, so the extractor of a 1917 revolver had something to push against to eject the rimless 45 ACP rounds. I don't care about moon clips because I am not in a hurry to reload at the range. I load my S&W 1917 revolvers the same way I load any other double action revolver. I put a round in each chamber, then close the cylinder. Could not care less about reloading fast.

Now let's back up the bus for a minute and consider why 45ACP revolvers were invented in the first place. Smith and Wesson realized that Colt was going to have trouble supplying enough 1911 pistols to the Army once we entered WWI in 1917. For S&W it was a simple conversion to take the basic 44 Hand Ejector, 2nd Model, chambered for 44 Special, and open up the chambers and the bore just a tad for the 45 ACP cartridge. Barrel length was fixed at 5 1/2", an unusual barrel length for S&W. And they realized the extra .030 of space behind the cylinder would be needed for the moon clips (actually half moon clips back then), clipped onto the 45 ACP rounds. S&W took the idea to the Army, and the Army jumped at it. So S&W won a contract to supply 163,600 45 ACP revolvers to the Army. These revolvers were produced between September 1917 and January 1919. Later on, the Brazilian contract helped save S&W's bacon during the Depression in the 1930s.

And just so we all know, you can fire 45 ACP rounds in a S&W Model 1917 without clips, because the cartridges headspace on the case mouth. I've done it lots of times. You just have to have a stick handy to poke out the empties. Not a big deal if you are not in a hurry.

 

[CraigC]

Until they invent a moon clip that loads itself, I wouldn't fool with them. That said, my ideal .45ACP revolver would be a Ruger Old Model .357Mag Blackhawk rechambered and fitted with a new 4" barrel.

 

[mcb]

Until they invent a moon clip that loads itself, I wouldn't fool with them. That said, my ideal .45ACP revolver would be a Ruger Old Model .357Mag Blackhawk rechambered and fitted with a new 4" barrel.

Again with the crazy talk.

Not my videos but a good representation of how effective the BMT mooner is:
Rimmed Cartridge:

Rimless Cartridge:

I don't understand the moonclip dislike here. I load them ahead of time and when I get to the range I spend my time shooting, practicing, working on skills, not fumbling with ammunition. When I get home I unload the moonclips at my leisure with no time wasted at the range chasing loose brass.

Not to mention all the fun and satisfaction of shooting a USPSA or IDPA match with a noble round gun, teaching the loathsome bottom feeders how to shoot properly.

 

[444]

I would assume the 625 handles auto rim cases just fine. I have a Model 25 and I use auto rim brass all the time.
I have moon clips and have shot with them extensively but to me, it is just an added chore that I don't want or need. Thus, I bought 500 auto rim cases and use them in that gun exclusively. I also have a 1917 revolver, but I can not see the sights on it; I shoot handguns mainly at a club indoor range and there just isn't enough light for my eyes to see the sights clearly. I suppose outdoors I could see them, but if I am outdoors I am shooting rifles.

 

[Jim Watson]

Don't forget, guys, Colt had a piece of that 1917 contract, too. Although S&W designed the half moon clip - actually a number of them, the cheapest and simplest chosen for mass production - they agreed for Colt to use it to supplement 1911 production, too. Colt made .45 ACP/AR New Service revolvers up until WWII when they dropped almost all handgun production except 1911A1.

That said, my ideal .45ACP revolver would be a Ruger Old Model .357Mag Blackhawk rechambered and fitted with a new 4" barrel.

Sorry, Craig, Skeeter Skelton et al found that .44 Special was about as big as an OM .357 could be made to hold. Strange, you could get .45 ACP SAAs (very rare, but Christie sold a fair number of cylinders), and can still get Italian copies in .45-.45 convertible.

 

[CraigC]

I don't understand the moonclip dislike here.

It's not dislike, it's just preference. I understand how they work and why people like them, that is obvious. I don't think it's terribly difficult to load and unload them either. However, I also don't shoot IDPA, USPSA or anything else. I don't think you're getting the point. You are spending a good bit of time and effort to load and unload those moon clips before and after your range time so that your range time is more efficient or your match reloads are quicker. For some folks, there is no point in all that.

Sorry, Craig, Skeeter Skelton et al found that .44 Special was about as big as an OM .357 could be made to hold. Strange, you could get .45 ACP SAAs (very rare, but Christie sold a fair number of cylinders), and can still get Italian copies in .45-.45 convertible.

Not only has this been done by custom gunsmiths but Ruger even produces a .45 convertible on the mid-frame as we speak. Not to even mention the .45 New Vaquero. The .44Spl is the most performance you can get out of the Old Model .357 but .45's are also easily done as long as they are only fed loads that do not exceed .45ACP pressures. It's only a matter of deciding the fine details and placing a phone call to Andy Horvath to get the ball rolling.

 

[mcb]

Apparently in the rush to get them going some of the early Colt 1917's did not have proper 45ACP chambers (just 45 ACP length 45 Colt chambers) and will not head space 45 ACP without the moonclip.

 

[DPris]

First Colt 1917s had through-bored chambers, without the internal step-down.
They would not headspace ACPs without clips.
At some later point, the chambers were properly bored with the stepdown that would headspace ACPs on the case mouth, and those guns could fire without clips.

Smiths used to reliably headspace ACPs without clips, but in recent years you couldn't count on it.
Older ones do, newer ones are questionable.

As for the clips- many of us simply don't like the additional hassle.
The idea of using Auto Rims to avoid clips is perfectly valid.
Denis

 

[Jim Watson]

I have been reading about the "bored through Colt 1917 cylinders" for ages.
Has anybody here actually got one? Seen one? Have a picture of one?
Supposedly they made 50000 of them, almost 1/3 of production, they ought to be all over the place.
I have heard reliably of one or two, but seen nothing.

Craig, I would sure like to see even a picture of a .45 Old Model .357. Current "mid frame" and New Vaqueros are not the same.

 

[Driftwood Johnson]

I don't understand the moonclip dislike here. I load them ahead of time and when I get to the range I spend my time shooting, practicing, working on skills, not fumbling with ammunition. When I get home I unload the moonclips at my leisure with no time wasted at the range chasing loose brass.

What you don't understand is different strokes for different folks.

When I bring a few revolvers to the range, I am there for a relaxing afternoon. Whether it's a 22, 38, or 45, whether it's a S&W or a Colt SAA, my idea of a good time at the range is relaxed shooting. One of my favorite ways to spend time with a revolver is bouncing soup cans around at the 25 yard berm.

I do all my competitive shooting at the Trap Field. I am not at the pistol range 'practicing, or working on skills'. I am just having relaxed fun. I don't need to reload fast. Try reloading a SAA fast sometime. Chasing loose brass? We're talking revolvers here, not semi-autos. I eject the empties into my hand, then dump them into whatever is handy to take them home to tumble and reload. Fumbling ammunition? Maybe I would if I was in a hurry, but as I think I have explained now, I am not in a hurry. Drop a round onto the ground? Yeah, every once in a while. What's the big deal? I wipe it off to make sure there is no grit on the bullet, then load it up.

Different strokes for different folks. You go ahead and use moon clips, I made the decision years ago not to bother. 45 Auto Rims eject fine from a S&W 1917 without clips.

 

[Vern Humphrey]

In every modern revolver I've seen, there is a "step" (for lack of a better term) in the cylinder, and the mouth of the cartridge case sits at that step.

This step is what prevents me from loading a 357 into my 38, or a 44 magnum into my 44 special, or (for that matter) a 45 Colt into my 45 ACP.

If I were to face the entire back off my 45 Colt cylinder, so as to allow me to use either 45 ACP or 45 AR in it, while the back of the cylinder would no longer touch the Colt's rim, wouldn't the step still allow it to headspace correctly? The mouth of the case would rest on the step, just like it does when I shoot ACP in my 1917 without using moon clips.

Why wouldn't that work?

The "step" in question is the throat. This is a reduced diameter area of the chamber just in front of where the bullet lies when a cartridge is chambered. It is there to receive and control the bullet when it exits the case, not to headspace the cartridge. If you loaded cartridges so the throat acted to headspace the round, you would drive up pressures considerably.

Some automatic pistol cartridges do headspace on a ledge in the chamber, but these are peculiar to that cartridge. If you had a ledge in your chamber that would headspace a .45 Colt (1.285" long) it would not work for a .45 ACP (0.898" long).

 

[Vern Humphrey]

I have been reading about the "bored through Colt 1917 cylinders" for ages.
Has anybody here actually got one? Seen one? Have a picture of one?
Supposedly they made 50000 of them, almost 1/3 of production, they ought to be all over the place.
I have heard reliably of one or two, but seen nothing.

Craig, I would sure like to see even a picture of a .45 Old Model .357. Current "mid frame" and New Vaqueros are not the same.

The "bored through" Colts will not take a .45 Colt -- like those with stepped chambers, they rely on half moon clips, which means the headspace is too great for the .45 Colt cartridge.

 

[mcb]

What you don't understand is different strokes for different folks.

When I bring a few revolvers to the range, I am there for a relaxing afternoon. Whether it's a 22, 38, or 45, whether it's a S&W or a Colt SAA, my idea of a good time at the range is relaxed shooting. One of my favorite ways to spend time with a revolver is bouncing soup cans around at the 25 yard berm.

I do all my competitive shooting at the Trap Field. I am not at the pistol range 'practicing, or working on skills'. I am just having relaxed fun. I don't need to reload fast. Try reloading a SAA fast sometime. Chasing loose brass? We're talking revolvers here, not semi-autos. I eject the empties into my hand, then dump them into whatever is handy to take them home to tumble and reload. Fumbling ammunition? Maybe I would if I was in a hurry, but as I think I have explained now, I am not in a hurry. Drop a round onto the ground? Yeah, every once in a while. What's the big deal? I wipe it off to make sure there is no grit on the bullet, then load it up.

Different strokes for different folks. You go ahead and use moon clips, I made the decision years ago not to bother. 45 Auto Rims eject fine from a S&W 1917 without clips.

I guess if your going to use 45AR instead of 45 ACP on moonclips would you not be better off with a similarly configured revolver in 45 Colt? 45 Colt has greater case volume for propellant and bullet making it a far more flexible and capable cartridge than 45ACP/AR. It seems the only advantage a 45 ACP revolver has over a 45 Colt revolver would be the use of moonclips for fast reloads.

 

[Jim Watson]

The "bored through" Colts will not take a .45 Colt -- like those with stepped chambers, they rely on half moon clips, which means the headspace is too great for the .45 Colt cartridge.

I didn't say anything about a .45 Colt.
I know what is being described, just that I have not seen even a picture of one, just many years of authoritative assurances that Colt, for some reason, forgot how or didn't bother to cut a chamber properly. Show me one.

 

[Vern Humphrey]

Smith and Wesson was originally contracted to provide revolvers in .45 ACP and they developed the half moon clip. Colt received a contract later, and the contract did not require a chamber ledge -- the half moon clip was thought to be enough. Later, the requirement for the ledge was added, so .45 ACP rounds could be fired without the half moon clip (although the fired cases would have to be shaken or poked out with a stick.)

 

[Jim Watson]

The absence of the guns is what mystifies me. Or do people just not notice or care? The Colt 1917 seems less common than the Smith even though they made approximately as many.

 

[Driftwood Johnson]

I guess if your going to use 45AR instead of 45 ACP on moonclips would you not be better off with a similarly configured revolver in 45 Colt? 45 Colt has greater case volume for propellant and bullet making it a far more flexible and capable cartridge than 45ACP/AR. It seems the only advantage a 45 ACP revolver has over a 45 Colt revolver would be the use of moonclips for fast reloads.

Actually, no.

Yes, 45 Colt has far more case capacity than 45 ACP or 45 AR. But that is because the cartridge was developed in 1873 for Black Powder. Black Powder is far less energetic than just about any modern Smokeless powder you can name. The case was that big so it could hold 40 grains of Black Powder. Black Powder must be compressed slightly. Any airspace left in a cartridge loaded with Black powder is a bad thing and can lead to unpredictable pressure spikes. So the 45 Colt cartridge case was designed to hold 40 grains of Black Powder, compressed slightly under a 250 grain bullet. 40 grains of Black Powder along with a 255 grain soft lead bullet made for a very powerful revolver cartridge for its day.

But in the Smokeless era, when you pour a stiff charge of modern powder inside the cavernous 45 Colt case, you wind up only filling the case slightly more than halfway. Same thing with 38 Special, another cartridge designed for Black Powder. Most 38 Special loads only fill the case up slightly more than halfway. So all that extra space in the old 45 Colt is wasted space. In fact, if you load it too lightly, you will start to get spotty ignition and incomplete burning of the powder. That's why you don't load 45 Colt below recommended minimums, the cartridge becomes inefficient and unreliable. By the way, that is why Trail Boss powder was invented. The donut shaped grains are very fluffy and take up lots of space in the big 45 Colt case, displacing much of the air, and allowing light loads to burn efficiently.

I don't load 45 Colt with Smokeless powder much these days, but when I did, my standard load was 7.5 grains of Unique under a 250 grain bullet. Not a barn stomper, a relatively mild load. That much powder did not take up much more than 1/2 of the case volume, but it was efficient enough that it burned consistently and velocity was consistent. Max load with a 250 grain bullet and Unique in my old Lyman Pistol and Revolver Handbook is 8.5 grains. The minimum load is 6.0 grains, and as I said it is not recommended to go below that. If I go over to the Thompson Center Contender only section, the Maximum load for 45 Colt with a 250 grain bullet is 11.5 grains of Unique. That will far exceed the industry standard SAAMI maximum pressure for 45 Colt of 14,000 PSI. We could argue all day about whether or not the Maximum pressure SAAMI standard for 45 Colt is pertinent for modern revolvers made of modern steel, but most of my 45 Colt revolvers are pretty old and will not take Thompson Center or "Ruger Only" loads without blowing up. So as far as being a 'far more flexible and capable cartridge than 45ACP/4AR', it is a moot point. If I load up 45 Colt to near 44 Mag pressures and fire it in any of my guns, they would probably blow up.

45 Auto Rim on the other hand has the exact same interior volume as 45 ACP. It can be loaded with the same dies, and more importantly, it can be loaded with the same data as 45 ACP. 45 ACP was developed in the Smokeless era and was designed around Smokeless powder. The interior capacity of the round is better suited to Smokeless powder, there is not as much empty airspace inside after the bullet has been seated. This means the cartridge can develop the same velocity and pressure for the same bullet with less powder than 45 Colt can. I load 45AR relatively mild, with a 200 grain bullet and 5.5 grains of Unique. Even so with this mild load there are no unburnt powder grains and the cases come out quite clean. The same cannot be said for 45 Colt with a light load. The hottest Unique load for 45 AR in my Lyman book is 6.6 grains of Unique under a 230 grain bullet. When you get right down to it, 45 AR (and 45 ACP) is a much more efficient cartridge than 45 Colt is with Smokeless powder, unless you are going to load 45 Colt to 'Ruger Only' pressures in a very strong gun. But for an old gun such as this S&W Model 1917, made in 1918, it is a very efficient and useful cartridge.






Just so we understand what we are talking about, the five cartridges in this photo, left to right, are 45 Colt, 45 Schofield, 45 Cowboy Special, 45 Auto Rim, and 45 ACP. Both 45 Colt and 45 Schofield are Black Powder era cartridges, and since they were stuffed full of powder, the comparative size of the two cases is a good indicator of their comparative power when loaded with Black Powder. 45 Cowboy Special is a cartridge developed for light Smokeless loads in 45 caliber revolvers in Cowboy Action Shooting. It shares the exact same rim configuration as 45 Colt, but it has the same interior capacity as 45 ACP or 45 AR. Since it shares the same rim configuration of 45 Colt, it can be fired in any 45 Colt revolver. And since it has the same interior capacity as 45 ACP and 45 AR it can be loaded with the same data as either of them. Since the internal volume is far less than 45 Colt, when loaded lightly, the powder will burn consistently without soot or unburnt powder grains. Lastly, you can see how much thicker the .090 thick rim is on the 45 AR cartridge than the .060 thick rim of 45 Colt, 45 Schofield and 45 CS.

 

[CraigC]

Craig, I would sure like to see even a picture of a .45 Old Model .357. Current "mid frame" and New Vaqueros are not the same.

Cylinders of the current mid-frames are the same diameter. I've seen and handled custom OM .45's and talked to several gunsmiths about building them. No issues with doing so, just never pulled the trigger on it.

 

[mcb]

Actually, no.

Yes, 45 Colt has far more case capacity than 45 ACP or 45 AR. But that is because the cartridge was developed in 1873 for Black Powder. Black Powder is far less energetic than just about any modern Smokeless powder you can name. The case was that big so it could hold 40 grains of Black Powder. Black Powder must be compressed slightly. Any airspace left in a cartridge loaded with Black powder is a bad thing and can lead to unpredictable pressure spikes. So the 45 Colt cartridge case was designed to hold 40 grains of Black Powder, compressed slightly under a 250 grain bullet. 40 grains of Black Powder along with a 255 grain soft lead bullet made for a very powerful revolver cartridge for its day.

But in the Smokeless era, when you pour a stiff charge of modern powder inside the cavernous 45 Colt case, you wind up only filling the case slightly more than halfway. Same thing with 38 Special, another cartridge designed for Black Powder. Most 38 Special loads only fill the case up slightly more than halfway. So all that extra space in the old 45 Colt is wasted space. In fact, if you load it too lightly, you will start to get spotty ignition and incomplete burning of the powder. That's why you don't load 45 Colt below recommended minimums, the cartridge becomes inefficient and unreliable. By the way, that is why Trail Boss powder was invented. The donut shaped grains are very fluffy and take up lots of space in the big 45 Colt case, displacing much of the air, and allowing light loads to burn efficiently.

I don't load 45 Colt with Smokeless powder much these days, but when I did, my standard load was 7.5 grains of Unique under a 250 grain bullet. Not a barn stomper, a relatively mild load. That much powder did not take up much more than 1/2 of the case volume, but it was efficient enough that it burned consistently and velocity was consistent. Max load with a 250 grain bullet and Unique in my old Lyman Pistol and Revolver Handbook is 8.5 grains. The minimum load is 6.0 grains, and as I said it is not recommended to go below that. If I go over to the Thompson Center Contender only section, the Maximum load for 45 Colt with a 250 grain bullet is 11.5 grains of Unique. That will far exceed the industry standard SAAMI maximum pressure for 45 Colt of 14,000 PSI. We could argue all day about whether or not the Maximum pressure SAAMI standard for 45 Colt is pertinent for modern revolvers made of modern steel, but most of my 45 Colt revolvers are pretty old and will not take Thompson Center or "Ruger Only" loads without blowing up. So as far as being a 'far more flexible and capable cartridge than 45ACP/4AR', it is a moot point. If I load up 45 Colt to near 44 Mag pressures and fire it in any of my guns, they would probably blow up.

45 Auto Rim on the other hand has the exact same interior volume as 45 ACP. It can be loaded with the same dies, and more importantly, it can be loaded with the same data as 45 ACP. 45 ACP was developed in the Smokeless era and was designed around Smokeless powder. The interior capacity of the round is better suited to Smokeless powder, there is not as much empty airspace inside after the bullet has been seated. This means the cartridge can develop the same velocity and pressure for the same bullet with less powder than 45 Colt can. I load 45AR relatively mild, with a 200 grain bullet and 5.5 grains of Unique. Even so with this mild load there are no unburnt powder grains and the cases come out quite clean. The same cannot be said for 45 Colt with a light load. The hottest Unique load for 45 AR in my Lyman book is 6.6 grains of Unique under a 230 grain bullet. When you get right down to it, 45 AR (and 45 ACP) is a much more efficient cartridge than 45 Colt is with Smokeless powder, unless you are going to load 45 Colt to 'Ruger Only' pressures in a very strong gun. But for an old gun such as this S&W Model 1917, made in 1918, it is a very efficient and useful cartridge.

View attachment 768943




Just so we understand what we are talking about, the five cartridges in this photo, left to right, are 45 Colt, 45 Schofield, 45 Cowboy Special, 45 Auto Rim, and 45 ACP. Both 45 Colt and 45 Schofield are Black Powder era cartridges, and since they were stuffed full of powder, the comparative size of the two cases is a good indicator of their comparative power when loaded with Black Powder. 45 Cowboy Special is a cartridge developed for light Smokeless loads in 45 caliber revolvers in Cowboy Action Shooting. It shares the exact same rim configuration as 45 Colt, but it has the same interior capacity as 45 ACP or 45 AR. Since it shares the same rim configuration of 45 Colt, it can be fired in any 45 Colt revolver. And since it has the same interior capacity as 45 ACP and 45 AR it can be loaded with the same data as either of them. Since the internal volume is far less than 45 Colt, when loaded lightly, the powder will burn consistently without soot or unburnt powder grains. Lastly, you can see how much thicker the .090 thick rim is on the 45 AR cartridge than the .060 thick rim of 45 Colt, 45 Schofield and 45 CS.

View attachment 768944

Great background information for this thread!

But that does not change the fact that 45 ACP in a revolver offers no ballistics advantage over 45 Colt, even when loading strict SAAMI MAP loads. Set the history that brought us both cartridges and historic collectible revolvers aside, the only advantage a modern 45 ACP revolver offer is cheaper factory ammunition and the ability to use robust moonclips with short cartridges for a faster reloads. If neither of those factors are important to you then a 45 Colt revolver is likely a better choice even if you are staying strictly within the low SAAMI MAP for 45 Colt.

 

[Jim Watson]

Once upon a time, it was thought that the thick rim of the .45 AR indicated a thick, strong case and overloading it in the 1950 and 1955 series S&Ws was published. Wish I still had my collection of Handloader's Digests, there was an article in one of them that would curl your hair.

Once upon a time, 10 grains of Unique was thought a suitable heavy .45 Colt load.

I understand that the .45 Cowboy Special is not only a good light smokeless cartridge, it will also hold the SASS black powder category minimum of one C.C. (Lee scoop) of black powder with a 170 grain bullet.

Interesting dichotomy, there is "Ruger only" load data and small shop ammo all over the place. Ask Ruger? No such thing, the guns are only "rated" for standard "nitro for black."

I've seen and handled custom OM .45's and talked to several gunsmiths about building them.

I wonder what they know that Skeeter's gunsmiths didn't.

"The past is a different country. They do things differently there." Cooper

 

[Driftwood Johnson]

I understand that the .45 Cowboy Special is not only a good light smokeless cartridge, it will also hold the SASS black powder category minimum of one C.C. (Lee scoop) of black powder with a 170 grain bullet.

Almost correct. There is no definition of bullet weight in the SASS Smoke Standard.

Here is the wording from the SASS Shooter's Handbook:

"Blackpowder category contestants are expected to understand they will contend with smoke obscured targets. To ensure this, all shotgun, revolver, and rifle powder charges must produce smoke at least equivalent to a baseline load of 15 grains by volume (1 cc) of blackpowder."

This standard was adopted a few years ago when it was noticed a few gamers were winning in the Black Powder categories without producing much smoke. I actually wrote that first sentence, but I see my wording has been changed ever so slightly. The idea was we shoot Black Powder, to paraphrase JFK, 'not because it is easy but because it is hard'.

It just so happens that the 45 Cowboy Special cartridge will hold enough Black Powder to make a good smoke cloud, but it was invented for light Smokeless loads.

 

[Driftwood Johnson]

the only advantage a modern 45 ACP revolver offer is cheaper factory ammunition and the ability to use robust moonclips with short cartridges for a faster reloads.

Yes, 45 ACP ammo is often cheaper than 45 Colt ammo, that is a definite advantage. I'm not going to belabor the bit about fast reloads with clips any more.

When I bought this 45 Colt/45 ACP convertible Blackhawk in 1975 I did not care about the 45 ACP cylinder. Like the dope I was back then I tried to buy it without the extra cylinder. In fact, it was many years before I ever even used the 45 ACP cylinder. No, it is not for sale. Yes, I could probably shoot so called 'Ruger Only' loads in this revolver, but I ain't interested in that.






Even though I have lots of Single Action revolvers chambered for 45 Colt, for some reason I have never been interested in Double Action revolvers chambered for the cartridge. Dunno why, they just don't interest me and I pass them by all the time. I much prefer my Smiths to be 44s. 44 Special or 44 Russian. Anyway, this Colt New Service that was made in 1906 is the only 45 Colt Double Action revolver I own. I bought it because it is so cool. Obviously I am never going to fire hot loads in it.

 

[Vern Humphrey]

Your Colt New Service should do just fine with fairly stiff (19,000 PSI) loads -- note the smokeless powder proof mark (on the trigger guard, just below the frame.) The New Service worked fine with .45 ACP, which is loaded to higher pressures than the .45 Colt, has a larger cylinder (and hence thicker chamber walls) and an off-set bolt stop which does not compromise chamber wall thickness.

 

[CraigC]

But that does not change the fact that 45 ACP in a revolver offers no ballistics advantage over 45 Colt, even when loading strict SAAMI MAP loads.

A few observations. First and foremost, most guns these days chambered in .45Colt have oversized chambers and chamber throats can be either way. Very few are spot on. This is why many go to the trouble of rechambering .41 and .44 cylinder to get proper .45 chamber dimensions. In a single action, the .45ACP is desirable for a few reasons. First is cheap hardball ammo. You don't always wanna spend an hour at the loading bench before you shoot the damned thing. Second, if you do reload, the .45Colt is a lot of wasted powder capacity. It takes more powder to get the same velocity. Third, the .45Colt is a very long case. The short .45ACP offers quicker, more positive ejection of empties. Important to someone who runs a single action fast, like myself. Fourth, it also means we can carry a reload in the form of a 1911 magazine.

I wonder what they know that Skeeter's gunsmiths didn't.

I honestly don't know and don't remember the Skeeter reference to this issue. The OM .357 cylinder is the slightly larger in diameter than the Colt SAA and the same as the Uberti and USFA replicas. As I said, you get more performance out of the .44Spl but the .45ACP is feasible. It used to be that 'some' gunsmiths wouldn't do it because they feared "Ruger only" loads finding their way into them but that's about it.