AUTO RIM AMMO

The only extra expense for reloading .45AR is a #17 shellholder. Midway has them for $6.79. Everything else is the same as .45ACP.
 
For Lee it's a #13 shell holder.

I shot a lot of Remington 45AR when I had my first 5 screw Model 1955

Now that I have another 5 screw 1955 and a frankenstein built on a Model 57 frame I have not loaded any 45AR but have 200 unfired Remington cases sitting hear.

When I reloaded 45AR in the 60s and 70s I used 200gr cast bullets from H&G molds and factory copper cased 185gr SWC over 3.5gr of Bullseye.
 
Not if you load on a Forester, it requires a different set of jaws to handle the thicker rim. Don't care, still the best single station press.
 
One of the side benefits of the Auto Rim case is the ability to handle some really neat bullets that just don't feed well from a moonclip set.
There are several full wadcutter bullets out there in the 210-225-235 grain weight area that are flat as a pancake, load in an almost flush position, have one heck of a frontal area and punch great big clean holes in the target. The Penn Bullet 225 gr. DBBWC in my 25-2 is a consistent one-hole shooter at 25 yards!
 
Virtually the only Auto Rimmed ammo available is Buffalo Bore that comes in 20 round boxes for about $1.80 per round. That's ridiculous. I load my own in new RP virgin brass with 200 grain lead H&G bullets. If I want factory ammo I use moon clips and factory 45ACP.
 
I had found a site were a guy did extensive ammo testing with a 25-2 . the results were all listed very carefully with all the load specs. his conclusion was wc bullets performed better than round nose.his theory was round nose could cant in a revolver seeing it was designed for auto. as far as the moon clips,the guy I got this from made a tool from a piece of stainless. he ground a relief on the end of tube and it cams the empties right out no sweat. if anyone wants a pic i will post one,let me know
 
I had found a site were a guy did extensive ammo testing with a 25-2 . the results were all listed very carefully with all the load specs. his conclusion was wc bullets performed better than round nose.his theory was round nose could cant in a revolver seeing it was designed for auto.

Cant in a revolver. That's rich. .44 special is renowned with 246 grain round nose in a revolver. .45 ACP ball has a considerable amount of bearing and cant isn't even possible with that bullet. I think they guy who did the extenswive testing is probably full of prunes as Jack O'Conner was fond of saying.
 
I am among those who have never fired a round of factory .45 AR, but formerly reloaded it (it's been awhile since I have done that). When I did, I used the same load recipes as I use for .45 ACP. I remember an article in, I think, G&A some years ago where they were providing what I thought were some horrendously hot loads for the .45 AR, with MVs well over 1000 ft/sec.

I believe Ron Terrell (not sure of spelling) wrote an article in one of the 1967 issues of G&A. His loads, in a S&W 1917, produced velocities >1000 fps. I think he used Herco and the gas checked equivalent of 452423.

Unfortunately I threw out my old gun magazines when I moved and no longer have that issue.
 
.45 Auto Rim's maximum chamber pressure (SAMMI specs) is 16,900 c.u.p. That's 3,000 less pressure units than standard .45 ACP. It is generally factory- (R-P has a real factory) loaded with a swaged lead bullet, so it should be more than safe in a sound 1917 S&W or Colt, which is why it was and is loaded originally.

Most of the older Speer handloading manuals showed a 250 grain swaged SWC over 6.2 grains of what was old Unique for 824 fps. which is better than R-P or W-W 250-255 grain .45 Colt. And it does it at 3,000 c.u.p. LESS pressure than SAMMI uses as the maximum pressure for .45 ACP!

My standard handload for .45 AR is a home-cast Lyman 454424 SWC which is about 260 grains of ex-wheelweight over that charge of old Unique, of which I am almost out. Every 1917, 1955-Model 25-2, 625 or Colt New Service I have shot this in loves it.

If I could afford it, I'd shoot a lot of factory-loaded Auto Rim. I can't so I don't.
 
I have a couple three revolvers in .45 ACP. I find the clips a pain, therefore I use the Auto Rim cases and speedloaders (HKS #25).

Both the 1917 revolvers (Colt and Smith & Wesson) were chambered for .45 ACP. The then-standard .45 ACP round were issued and used in both revolvers routinely.

The .45 Auto Rim case was introduced in about 1923 - after the Great War. The round was introduced by Peters (later bought out by Remington), made and sold for a number of years. It was later marketed as 'Remington-Peters' and then just 'Remington'. That line of ammunition was always loaded with lead bullets and velocities were subdued for some reason. One source I read says it was to prevent excess wear on the old revolvers, but I find that lacks reason.

The SAAMI pressures were derived from the original Peters loading, not based on the limits of the revolvers used. So the pressure limits of .45 Auto Rim is listed as 'less' than .45 ACP, but the firearms are the same and the cases are suited for equal use.

I have fired G. I. ball .45 caliber cartridges from both makes of 1917 revolvers and the S&W 1955 target model with no adverse affects. .45 ACP data can be used with .45 Auto Rim cases without fear of overloads. I must admit firing them sounds like the crack of doom, but they are not dangerous.

However, as the revolver incarnations don't have the limitations imposed by semi-automatics on bullet shape and weight, I like using 255 grain lead bullets (designed for .45 Colt) and a slower pistol powder. Yes, the .45 Colt bullet is theoretically .454" vice .452" for .45 ACP barrels, but working from a starting load, the bullet swedges down without difficulty. I have a number of such rounds as we speak and I've fired a number of them already.

I commonly use Starline brass, but the older Remington and R - P brass seems to work well. (I found it simpler to get a 'pile' of Starline brass for a new - to me - revolver.)

Speer manuals #13 and #14 have further specifics.

Using a CED chronograph, my four inch (cut down) model 25 revolver delivers 794 average velocity for a 12 round sample. This is NOT a maximum loading, but seems sufficient to the purpose and I have nothing to prove in terms of how much recoil I can handle.

Lighter loads are equally as easy using lighter bullets and smaller doses of faster powder, much like .45 ACP.

I find I get more positive ignition with the rimmed rounds than with clips. And to my mind, it's simpler, but I'm an old revolver guy.
 
I load the hell out of 45AR, its a fun load to shoot and reload. I only have a 1917 in 45autorim, but I am working on that.

I like a 215grn SWC that I cast my self, moving about 850fps, its is more accurate than I am. :P and it puts nice holes in the paper, or will ring steel just fine. Hell it works great for knocking bowling pins off of tables with authority.
 
".45 Auto Rim's maximum chamber pressure (SAMMI specs) is 16,900 c.u.p. "

Where did that information come from? The latest published SAAMI (not SAMMI) pressure and velocity standards (1/2013) show the .45 AR Transducer MAP, MPLM, and MPSM all to be "N/E" (Not Established).
 
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I also have a 25-2, and a 625 as well. I only used moon clips when I competed with the 625. For casual target shooting, they are unnecessary.
If I carried the 625 it would be with moon clips. I will never carry the 25-2. I considered getting some 45 auto rim cases, but decided the negatives outweighed the positives.
 
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"Where did that information come from?"

Speer #11, and several earlier editions of Speer's, for one source. It could well be that SAMMI has not yet established standards in the current manner of pressure measurement for some older rounds like .45 Auto Rim, but the old CUP data isn't useless, by any means, as it is useful comparing other loadings that were tested with the same units of measure.

If the old system measured one round at 15,000 CUP and another round at 20,000 CUP using that same system, the lower numbers represent less pressure than the higher, regardless of what another system uses to measure pressure.

If Johnny can eat 4 apples, and Bobby can eat 8 apples, it may not tell us how many bananas each can eat but it'll be a given that Bobby will be able to eat more bananas than Johnny.
 
This has devolved from a discussion of the .45 AR to arguments about about pressure! The silliest remark I see is that Copper Crusher pressure measurements are "meaningless"!

For over a century Copper Crusher pressure measurement was the only "game in town". Results from this measurement were always expressed as PSI! This only changed after Piezoelectric pressure measurements became the norm during the past 30 years or so. Piezoelectric equipment measurements were originally referred to as PSIG(guage), and later as PSI Absolute. To differentiate between this and older information the older Copper Crusher data came to be referred to as PSI Crusher, and, finally, Copper Units of Pressure (CUP), since there was still confusion as there was so much published information still out there referring to crusher pressures as PSI. Many people believed, and still believe(!) that the measurements are the same and the difference in numbers is a result of "dumbing down" of data for legal reasons, which is even sillier!

SAAMI currently shows both Piezo PSI pressures and CUP pressures, but in different tables. The Current SAAMI pressure standard for .45 AR is 15,000 CUP MAP (Maximum Average Pressure). All the NE (Not Established) notation in the "Transducer" (Piezo) table means is there either has been no reason to re-shoot the cartridge, or an economic decision has been made to not re-shoot data for what are basically obsolete or archaic cartridges There are many relatively low pressure cartridges for which Transducer data is "Not Established".

What is meaningless from a shooters/reloaders perspective is any discussion of pressure specifications! We can't do anything about it when using factory ammunition, and we have absolutely no way of measuring it for our hand-loaded ammunition except trusting data published by the reloading equipment, bullet and powder manufacturers!

One thing most do not understand is that SAAMI Pressure Standards are not absolute! They are nominal standards established by the firearms and ammunition industries. These standards are voluntary compliance for the ammunition industry! There is no reason to believe that ammunition loaded within a reasonable variance from these standards is dangerous! The best example is what has come to be known as +P for several cartridges, where the +P pressure standard typically exceeds "Standard Pressure" by 17-20%.
 
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"Where did that information come from?"
That, sir, is an excellent question. One that is probably not asked enough in general. I read - and sadly cannot remember the source right now - the SAAMI specifics on chamber pressure (which D Walt says has been changed to 'Not Established' relatively lately) is derived from the commercial .45 AR lead bullet loading; which ignores the regular .45 ACP (in military loading).

I cannot puzzle out how there are two firearms which use the same ammunition and two different chamber pressure maximums.

Speer #11, and several earlier editions of Speer's, for one source.
If by that statement you mean the load 'maximums' which imply .45AR is NOT to be loaded to the same velocities as .45 ACP, there are manuals in addition to Speer which imply the same thing. Lyman #49 is one such (I just looked) and I seem to recall others, but I'm too lazy to dig them all out and check.

This may be one of those 'everybody knows' bits of ignorance that gets repeated and passed around continually - like 'fast' powders are for short barrels and any bullet .001" over bore size will blow up the firearm.

Once again; the 1917 revolvers were chambered for and used with regular G. I. ball ammunition all during the period the revolvers were used in U. S. Armed Forces Service. ONLY the commercial loading for .45 AR was reduced.

This is NOT to say a well preserved Model 1917 Colt or Smith & Wesson revolver - or even a well preserved Model 1911 or 1911A1 should be continually shot with G. I. equivalent ammunition "just because one can", but the notion a modern - 1950, 1955 or later - revolver in .45 ACP is somehow fragile simply - in terms of pressure - is nonsense.
 
"I cannot puzzle out how there are two firearms which use the same ammunition and two different chamber pressure maximums."

The cartridge we are discussing is only one example. If a firearm can shoot .45 Auto Rim, it likely can shoot .45 ACP. There are lots of others. The .38 ACP and the .38 Super; one led to the other. My .357 Magnums can shoot .38 Specials. The Magnum round was developed from the Special round. In a way, the Auto Rim round was developed from the ACP round. Two cartridges, same gun.

Perhaps you don't understand what "SAAMI specs" really means. SAMMI is, basically, a firearms industry group that tries to set standards for things like chamber dimensions and cartridge maximum pressures so that one maker's ammo can be safely shot in another maker's guns. It is to try to insure compatibility and safety. They establish guidelines for manufacturers to follow, they don't legally regulate anything. Manufacturers' following these guidelines is voluntary, and many overseas manufacturers, mostly in third world countries, don't seem to follow SAAMI guidelines very closely, based on my experience and the reported experiences of others.

"If by that statement you mean the load 'maximums' which imply .45AR is NOT to be loaded to the same velocities as .45 ACP..."

No, I didn't say or mean that at all. What I meant was that SAAMI recommends that factory loadings of various cartridges not exceed certain pressures, primarily for safety's and compatibility's sake.

Most American factory ammunition is loaded by commercial manufacturers to pressures much less than SAAMI's guidelines. There is usually a lower pressure for the product to give a safety cushion. Most handloading manuals' data was developed by them to stay within SAAMI's pressure guidelines unless the manual says that their data exceeds SAAMI's recommendations.

There is, so far, no system available to the home ammo loader to measure their loads' pressures. Following the component makers published data and using a chronograph to test your loads is about the best we have right now.

It is just a curious fact that SAAMI had put .45 Auto Rim's maximum recommended pressures lower than their own standard for .45 ACP. The developer of the .45 Auto Rim, the Peters Cartridge Company in 1920, used a lead instead of a jacketed bullet. It is just a guess on my part, but I bet that SAAMI's maximum pressure recommendation for the Auto Rim was probably based somewhat on measuring the pressures of the ammo company's existing product.

Frank Barnes' tome "Cartridges Of The World" says that the developer of the Auto Rim used a lead bullet to reduce wear to the rifling of the guns' barrels. The rim was just added to make use of the revolvers chambered in .45 ACP more convenient, he wrote. He also wrote that any load safe in the .45 ACP "can be used in the Auto Rim with about the same results."

Other than this, I don't know how to reply to your post because I don't understand what you are trying to say.
 
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Here's what Speer #11 actually says:
"Since many of the 45 Auto Rim revolvers have aged past the half-century mark, only modest pressure loads are safe and powder charges should not be increased."

Which makes no sense if those guns are still rated for .45acp which is what they (like the 1917s) were using to begin with. Using only watered -down AR loads would make sense if there were also a prohibition against regular .45acp ball ammo, but nobody says that. I'm also baffled by how "aging" can somehow make guns weaker.
 
Archie said:
"I cannot puzzle out how there are two firearms which use the same ammunition and two different chamber pressure maximums."

The cartridge we are discussing is only one example. If a firearm can shoot .45 Auto Rim, it likely can shoot .45 ACP.
Not exactly. No firearms are chambered and designated for use with the .45 Auto Rim cartridge. They are all chambered and designated for the .45 ACP round. The Auto Rim case was designed as a convenience, not an alternative.

BUFF said:
There are lots of others. The .38 ACP and the .38 Super; one led to the other.
Again, not exactly. The .38 ACP and the Super .38 are two different rounds - even though they use the same case. (I've often wondered why Colt ever did such a thing. Lawsuits and all.)
BUFF said:
My .357 Magnums can shoot .38 Specials. The Magnum round was developed from the Special round.
Not at all. The Magnum round was designed as a high pressure round and the makers extend the case .125" to make sure the higher pressure round doesn't fit into the lower pressure rated arm.

BUFF said:
In a way, the Auto Rim round was developed from the ACP round. Two cartridges, same gun.
Yes; they are both designed to be fired in a .45 ACP chamber. The Auto Rim is far more convenient to use in a conventional, double action, revolver. However, adding the flange does not weaken either the case or the arm. There exists no safety reason to down load the AR case.

By the way, you forgot to mention the problem between 9mm Parabellum and 9mm Glisenti. Same size as 9mm Parabellum, loaded to more or less .380 ACP pressures. They are different cartridges and intended for different pistols.

BUFF said:
Perhaps you don't understand what "SAAMI specs" really means.
Yes, I do.

Archie said:
"If by that statement you mean the load 'maximums' which imply .45AR is NOT to be loaded to the same velocities as .45 ACP..."

BUFF said:
No, I didn't say or mean that at all. What I meant was that SAAMI recommends that factory loadings of various cartridges not exceed certain pressures, primarily for safety's and compatibility's sake.
I understand what you wrote. Perhaps you do not understand with the powders available at the time the .45 Auto Rim was introduced, pressure and velocity were tightly linked. One could not reduce pressure without reducing velocity - in this specific example. Furthermore, the pressure level of the .45 Auto Rim was not reduced 'for safety's sake'. One notes SAAMI - or anyone else - did not ever issue a warning about shooting surplus G.I. ball .45 ACP ammunition in any revolver so chambered. (Or did I sleep through that?)

BUFF said:
There is, so far, no system available to the home ammo loader to measure their loads' pressures.
Yes, there are. I have two such devices.

BUFF said:
It is just a curious fact that SAAMI had put .45 Auto Rim's maximum recommended pressures lower than their own standard for .45 ACP. The developer of the .45 Auto Rim, the Peters Cartridge Company in 1920, used a lead instead of a jacketed bullet. It is just a guess on my part, but I bet that SAAMI's maximum pressure recommendation for the Auto Rim was probably based somewhat on measuring the pressures of the ammo company's existing product.
I believe I mentioned that possibility. The SAAMI limits effectively are set to duplicate the initial Peters loading, not the .45 ACP for which the arm is chambered and designed. I have no idea why; not only did they not ask me, they didn't even notify me they were in the process!

BUFF said:
Frank Barnes' tome "Cartridges Of The World" says that the developer of the Auto Rim used a lead bullet to reduce wear to the rifling of the guns' barrels. The rim was just added to make use of the revolvers chambered in .45 ACP more convenient, he wrote. He also wrote that any load safe in the .45 ACP "can be used in the Auto Rim with about the same results."
I just looked at CoTW. Yes, it confirms - at least repeats - the old theory the lead bullet was to reduce rifling wear.

I don't find the statement about 'safe loads' in CoTW #14; BUT I did find it appended to the loading data/factory loads chart in CoTW #8! The statement seems to have been left out in later editions. (Lawyers, maybe?) I fully concur with the thought. Why identify and chamber the revolver for use with .45 ACP ammunition, then expect no one would fire that ammunition?

BUFF said:
Other than this, I don't know how to reply to your post because I don't understand what you are trying to say.
Humpff? I thought I was pretty clear. A handgun chambered for .45 ACP and expected by both the manufacturer and owner - the U. S. Army - to fire standard .45 ACP ammunition should be considered safe to use reloaded ammunition suitable for .45 ACP pistols.

And modern made revolvers manufactured for .45 ACP - like the Smith & Wesson Model 1955 Target Revolver - should handle .45 ACP pressure levels without serious comment.

I do - in the manner of prudent handloaders for many, many winters - start at the low end of the load weight/pressure/velocity loading and work up until the velocity and accuracy is suitable or I reach the maximum load with the dire warnings.

I'm just a bit puzzled by your remarks, BUFF. You seemed to disagree with my thoughts, then you cited information confirming my methods and theories.

Oh. I'm not the first one to push the .45 Auto Rim up from the erstwhile factory pressures and velocities. One of the 'annuals' - and my brain has a drive belt slipping again - had an article called "Forgotten, but not gone!" and offered an essay on the .45 Auto Rim being loaded to the upper end of the acceptable spectrum.
 
I think I earlier mentioned a G&A article from many years ago about reloading the .45 AR which had some truly fearsome loads listed in it, well beyond typical .45 ACP performance. I was never tempted to go beyond the usual .45 ACP loadings. I may still have that article somewhere. It made an impression on me.
 

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