single action army clone

[RyanJames170]

So I was curious what people feel the Italian made single action army’s in 45 colt can handle for pressure, I only ask because SAMI lists 14,000 PSI how ever CIP lists 16,000 PSI and I’ve seen 45ACP models for sale. And this made me wonder as 45 acp is listed at 21,000 psi and if the guns were that week why would they chamber them for 45 acp

[M-Tecs]

SAAMI ammo recommendations are based on the weakest firearms commonly in use. That would be the iron blackpowder frame 1873 Colts. Todays 1873's are made form much better materials. Some also have increased cylinders size by .020" or .030".

They also chamber them in 44 Magnum.

https://www.guns.com/news/2019/02/13/if-cowboys-were-italian-traditions-1873-revolvers-by-pietta-video

https://www.traditionsfirearms.com/product/1873-single-action-revolver-44-mag-4.75-inch-barrel-color-case-hardened-sat73-800

https://www.uberti-usa.com/cartridge-revolvers/1873-cattleman

https://www.impactguns.com/revolvers/uberti-1873-callahan-44-mag-4-75-barrel-walnut-blued-6rd-037084999494-349322

https://www.shootingillustrated.com/content/new-for-2019-pietta-1873-single-action-series/

[racepres]

They also chamber them in 44 Magnum.

Speaks Volumes... no added info necessary!!!

[Green Frog]

I have a Uberti SAA 45 Colt sold by Taylor as their "Smokewagon" model with Taylor Tuning. I mostly shoot it with wax bullets driven by shotgun primers (Cowboy Fast Draw) but wouldn't hesitate to shoot any load recommended for the strongest revolvers chambered for 45 Colt. It has the advantages of the old SAA basic design supplemented by modern steel. OTOH, I wouldn't try to get 44 mag performance out of it!

Froggie

[M-Tecs]

) but wouldn't hesitate to shoot any load recommended for the strongest revolvers chambered for 45 Colt. It has the advantages of the old SAA basic design supplemented by modern steel.

Some of the hot loads specifically for the strongest 45 Colts will grenade 1873 clones.

Lots of "recommend loads" full size Ruger Blackhawks in the 34,000 PSI range. With the Redhawks and other some are loading the 45 Colts to the 45,000 to 50,000 PSI range.

https://singleactions.proboards.com/thread/32229/levels-colt-maximum-working-pressure

[35 Whelen]

It's become fairly common knowledge that Uberti's 1873 Single Actions in 45 Colt will handle loads in the 21-23K psi range, same as Ruger's New Vaquero. As the OP mentioned, they are chambered in 45 ACP whose SAAMI chamber pressure is 21K psi.

35W

[dogdoc]

Brian Pearce in Handloader magazine has some good commentary on this in his pet load column . I think it is in the one on +p 45 colt. I don’t have it in front of me but google is your friend.

[DougGuy]

SAAMI ammo recommendations are based on the weakest firearms commonly in use. That would be the iron blackpowder frame 1873 Colts.

SAAMI specs for original 45 Colt is for smokeless powder Colts. Push-pin Colts afaik. It is not recommended to use ANY smokeless powder loads in an old iron frame/black powder Colt. Many years ago there was much discussion on these guns and smokeless powder, there was a LOT of cautionary articles in the gun rags, and a lot of grenaded Colts.

I thought the early Italian clones to be of lacking quality in their metallurgy regardless of how well they fit the grips. Nowdays they are typically rated for 45ACP+P pressure of 23kpsi *IF* they are chambered in 45ACP. This would make the 45 Colt guns capable of the same pressure.

[shooting on a shoestring]

My 2 cents and 2 points:
First, not all Italian revolvers have the same metallurgy or specs. My FEELING is there was more variation in the earlier Italian revolvers. No scientific data to support it though. I would NOT extrapolate that just because one maker took an order from one distributor to make a run of 44 Magnum SAA clones, that all SAA clones have that metallurgy and heat treatment. I doubt they do. But, no data to support it.

Second, just because a revolver can keep from blowing up the first time it’s given a heavy load doesn’t mean the revolver will stand up to that for multiple heavy loads. If the cylinder is overly stressed, it will eventually fail. Maybe even with a lesser load after stress fractures have migrated. And of course frame stretching is how overly stressed revolvers most frequently display abuse.

I get that there’s no benefit in keeping pressure way below the capabilities of a particular revolver. But same is true for exceeding the capabilities. Problem is the only guidance is SAAMI specs, reloading manuals, people’s experience and worst of all…..opinions. I just expressed my opinion. No supporting data other than I own a some Italian revolvers, load for them and haven’t blown them up or shot them loose. Hope you do likewise.

[35 Whelen]

My 2 cents and 2 points:
First, not all Italian revolvers have the same metallurgy or specs. My FEELING is there was more variation in the earlier Italian revolvers. No scientific data to support it though. I would NOT extrapolate that just because one maker took an order from one distributor to make a run of 44 Magnum SAA clones, that all SAA clones have that metallurgy and heat treatment. I doubt they do. But, no data to support it.

Second, just because a revolver can keep from blowing up the first time it’s given a heavy load doesn’t mean the revolver will stand up to that for multiple heavy loads. If the cylinder is overly stressed, it will eventually fail. Maybe even with a lesser load after stress fractures have migrated. And of course frame stretching is how overly stressed revolvers most frequently display abuse.

I get that there’s no benefit in keeping pressure way below the capabilities of a particular revolver. But same is true for exceeding the capabilities. Problem is the only guidance is SAAMI specs, reloading manuals, people’s experience and worst of all…..opinions. I just expressed my opinion. No supporting data other than I own a some Italian revolvers, load for them and haven’t blown them up or shot them loose. Hope you do likewise.

I'm not aware of any Italian "clones" chambered in .44 Magnum. All of those I've seen are visibly larger in size than a Colt SAA and reproductions thereof.

Brian Pearce has addressed this subject a few times in the last few years, most recently within the last couple of issues of Handloader magazine. He states that Uberti's built/imported since 1990 are of the quality and metallurgy to handle Tier II 45 Colt loads. As already mentioned, if they're good to go with 45 ACP +P loads, why would it be any different with 45 Colt loads in the same pressure range?

EDIT-

Found one of the articles. In the Feb. issue of Handloader, of a current production Cimarron (Uberti) Model P in 45 Colt-

One significant departure of Cimarron/Uberti Model P revolvers when compared with the Colt SAA is the cylinder and frame size. The Colt cylinder measures 1.650 inches outside diameter, while the Model P measures 1.670 inches. The distance from the axis of the bore to the center of the base pin remains the same. This increases the outside chamber walls 0.010 inch, which adds significant strength over the locking bolt notches, the weak link in SAA revolver design. Combined with high tensile chrome-moly steel, this revolver can easily digest loads that generate 21,000 psi (the same as the .45 ACP).

35W

[RyanJames170]

That is good to know, that they can Handel the 21,000 psi

[Der Gebirgsjager]

My 2 cents and 2 points:
First, not all Italian revolvers have the same metallurgy or specs. My FEELING is there was more variation in the earlier Italian revolvers. No scientific data to support it though. I would NOT extrapolate that just because one maker took an order from one distributor to make a run of 44 Magnum SAA clones, that all SAA clones have that metallurgy and heat treatment. I doubt they do. But, no data to support it.

Second, just because a revolver can keep from blowing up the first time it’s given a heavy load doesn’t mean the revolver will stand up to that for multiple heavy loads. If the cylinder is overly stressed, it will eventually fail. Maybe even with a lesser load after stress fractures have migrated. And of course frame stretching is how overly stressed revolvers most frequently display abuse.

I get that there’s no benefit in keeping pressure way below the capabilities of a particular revolver. But same is true for exceeding the capabilities. Problem is the only guidance is SAAMI specs, reloading manuals, people’s experience and worst of all…..opinions. I just expressed my opinion. No supporting data other than I own a some Italian revolvers, load for them and haven’t blown them up or shot them loose. Hope you do likewise.

I like, and second your opinion!

DG

[gc45]

35 Whelan - Thanks for your post, very good to here. Think I read Brian's article as well but had forgotten it.
I may get an Italian clone 44 Special revolver because our American gun makers seen to care less these days what they make available and I am tired of waiting plus I refuse to pay Gunbroker prices; easy to see that America is happy to hand over firearm production to the Europeans.

[35 Whelen]

35 Whelan - Thanks for your post, very good to here. Think I read Brian's article as well but had forgotten it.
I may get an Italian clone 44 Special revolver because our American gun makers seen to care less these days what they make available and I am tired of waiting plus I refuse to pay Gunbroker prices; easy to see that America is happy to hand over firearm production to the Europeans.

I've owned two 3rd Generation Colt SAA's in .44 Special's, a 4 3/4" and a 5 1/2". I never even fired them. The actions were oversprung and gritty and they were worth more to a collector than to a shooter like myself. I have owned three Uberti .44 Special's for quite a few years now. An older 4 3/4", a 2011 Model P 5 1/2" and a 2018 Flat Top Target 7 1/2". They are all superbly accurate out to 100 yds. and are easy to load for. I also own several other Uberti's in .357 and 45 Colt and they're equally as well built and accurate.

35W

[DougGuy]

I've owned two 3rd Generation Colt SAA's in .44 Special's, a 4 3/4" and a 5 1/2". I never even fired them. The actions were oversprung and gritty and they were worth more to a collector than to a shooter like myself. I have owned three Uberti .44 Special's for quite a few years now. An older 4 3/4", a 2011 Model P 5 1/2" and a 2018 Flat Top Target 7 1/2". They are all superbly accurate out to 100 yds. and are easy to load for. I also own several other Uberti's in .357 and 45 Colt and they're equally as well built and accurate.

35W

Generally the Uberti guns are tighter than any off the shelf Ruger, so they have the potential to be 100yd guns, they fall into the same category of improvements as the Rugers, hone and uniform the cylinder throats, cut a nice forcing cone, and size to the throats. Very basic improvements but easily appreciated once at the range. The triggers are more often than not very liveable.

[M-Tecs]

SAAMI specs for original 45 Colt is for smokeless powder Colts. Push-pin Colts afaik. It is not recommended to use ANY smokeless powder loads in an old iron frame/black powder Colt. Many years ago there was much discussion on these guns and smokeless powder, there was a LOT of cautionary articles in the gun rags, and a lot of grenaded Colts.


Colt did not warranty the 1873's until 1900 or 1901 depending on the source. The push-pin was available for several years before Colt warrantied the 1873's for smokeless. Per R. L. Wilson's book "COLT An American Legend" the transverse base pin lock was added in 1892 and serial # 144,000 That is much sooner than the smokeless powder guns which were not introduced until 1900. Colt started stamping a smokeless proofed in 1900 or 1901.

What Colt did was well before SAAMI inception in 1926. This is total production numbers of all calibers but in 1926 2/3's of the Colts produced were before Colt warrantied the 1873 for smokeless. SAAMI would have been aware of that the majority of the most commonly used 45 Colt firearms not warranted by Colt for smokeless.

From day one SAAMI recommend 14,000 CUP/PSI as safe in all 45 Colt firearms.

Same for the 45/70 where 28,000 CUP/PSI are the same. Lyman recommends 18,000, some loading manuals recommend 21,000 and some others use the SAAMI recommendation of 28,000 CUP/PSI as Trapdoor safe.

Historically the 14,000 CUP/PSI may have been overly optimistic for the early 1873's. By today's standards it is considered to be unsafe to use 14,000 CUP/PSI loads in the non-proofed Colt 1873's.

Reality is very few (if any) of the old Colts have not been fired with smokeless loads at some point in their life. Some survived others didn't.

[Outpost75]

Also the advised that the SAAMI MAP is not the machine loading limit, but is the maximum statistical individual pressure, i.e. the sample average plus 3 standard deviations. Typical sample averages for standard .45 ACP are 17,500-18,500 psi. and 19,500- 20,500 for +P.

[Thundermaker]

I see some people presenting CUP and PSI as the same thing. They're not. Not remotely. 14,000 CUP is roughly 21,000psi.

Why hotrod the cartridge? There are 14,000 psi loads in my manuals that will push a 255gr bullet at 1,000fps. If you can't kill it with that, it'll live forever.

[M-Tecs]

I see some people presenting CUP and PSI as the same thing. They're not. Not remotely. 14,000 CUP is roughly 21,000psi.

Why hotrod the cartridge? There are 14,000 psi loads in my manuals that will push a 255gr bullet at 1,000fps. If you can't kill it with that, it'll live forever.

SAAMI doesn't agree in the case of the 45 Colt (14,000 CUP/PSI) and the 45/70 (28,000 CUP/PSI). There might be more but these are the only two instances that I am aware of that CUP and PSI are the same.

https://saami.org/wp-content/uploads/2023/02/SAAMI-Z299.3-2022-Centerfire-Pistol-Revolver-Approved-12-13-2022.pdf

page 20

312791

Correlating PSI and CUP
https://www.shootingsoftware.com/ftp/psicuparticle2.pdf

[barnetmill]

I'....................
EDIT-

Found one of the articles. In the Feb. issue of Handloader, of a current production Cimarron (Uberti) Model P in 45 Colt-

One significant departure of Cimarron/Uberti Model P revolvers when compared with the Colt SAA is the cylinder and frame size. The Colt cylinder measures 1.650 inches outside diameter, while the Model P measures 1.670 inches. The distance from the axis of the bore to the center of the base pin remains the same. This increases the outside chamber walls 0.010 inch, which adds significant strength over the locking bolt notches, the weak link in SAA revolver design. Combined with high tensile chrome-moly steel, this revolver can easily digest loads that generate 21,000 psi (the same as the .45 ACP).

35W
I always thought that the most stressed part of a revolver cylinder was the end of the cylinder where the bullets jumps the gap into barrel.
But the metal is thinnest for sure over the cylinder bolt notches.

[Thundermaker]

SAAMI doesn't agree in the case of the 45 Colt (14,000 CUP/PSI) and the 45/70 (28,000 CUP/PSI). There might be more but these are the only two instances that I am aware of that CUP and PSI are the same.

https://saami.org/wp-content/uploads/2023/02/SAAMI-Z299.3-2022-Centerfire-Pistol-Revolver-Approved-12-13-2022.pdf

page 20

312791

Correlating PSI and CUP
https://www.shootingsoftware.com/ftp/psicuparticle2.pdf

Math is math, whether SAAMI agrees or not.

That shows you how lazy SAAMI is. They also list .303 British and .30-40 Krag with the same max pressure, and they use the same headspace gauge for both, just because the case dimensions are similar.

[M-Tecs]

Math is math, whether SAAMI agrees or not.

That shows you how lazy SAAMI is. They also list .303 British and .30-40 Krag with the same max pressure, and they use the same headspace gauge for both, just because the case dimensions are similar.

https://saami.org/wp-content/uploads/2019/02/ANSI-SAAMI-Z299.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

Page 17 - 30/40 Krag MAP 40,000 CUP

Page 19 - 303 Brit MAP 45,000 CUP

Page 97 - 30-40 Krag headspace 1.787"

Page 107 - 303 Brit headspace 1.8513"

https://www.shootingtimes.com/editorial/americas-first-30-caliber-service-cartridge/99423
SAAMI pressure guidelines for the Krag are lower than for the .303 British. The Krag's maximum average pressure (MAP) is 40,000 CUP compared to 45,000 CUP for the .303. Both service rifles share the single locking lug design, so you'd think they would share pressure assignments. Instead, the difference came down to metallurgy, not parts configuration.

[Thundermaker]

https://saami.org/wp-content/uploads/2019/02/ANSI-SAAMI-Z299.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

Page 17 - 30/40 Krag MAP 40,000 CUP

Page 19 - 303 Brit MAP 45,000 CUP

Page 97 - 30-40 Krag headspace 1.787"

Page 107 - 303 Brit headspace 1.8513"

https://www.shootingtimes.com/editorial/americas-first-30-caliber-service-cartridge/99423
SAAMI pressure guidelines for the Krag are lower than for the .303 British. The Krag's maximum average pressure (MAP) is 40,000 CUP compared to 45,000 CUP for the .303. Both service rifles share the single locking lug design, so you'd think they would share pressure assignments. Instead, the difference came down to metallurgy, not parts configuration.


Ok, so they updated it. Great. I don't see how that relates to the portion of my post that you highlighted. Those headspace numbers are interesting, since those cartridges don't headspace on the shoulder, and the headphones gauges don't have a shoulder on them.

Anyway, all that is irrelevant to the OP's thread.

[Larry Gibson]

SAAMI specifications are what the industry loads the cartridges to for safety in most all firearms, particularly those the cartridges were originally made for. Yes, there are some exceptions/updates but SAAMI standards/specs are not what certain cartridges can be safely handloaded to in other firearms. The 45 Colt and 45-70 are examples. Consider the 222 Rem and 223 Rem and be safely loaded to US 5.56 pressures when chambered in the firearms (modern actions) that can also handle the 5.56 pressures (not SAAMI standardized). Also, the 303 Brit and 30-40 can be loaded, safely, to higher pressures in rifles such as P14s, M10 Ross's, Siamese Mausers and Ruger SS actions but SAAMI specs for both are held to original specifications for those cartridges.

SAAMI represents the industry not reloaders, so SAAMI specs are, again, what the industry adheres to. SAAMI specifications /specs are also considered as "standards" if any legal litigations come about.

[Thin Man]

I recall a friend's experience with pressures. He had bought a S&W M-1917 revolver that appeared clean and tight. Happy with his new purchase, he opened his reloading manual to the "45" bracket, gathered some boolits etc. and set to handloading. When he got to his range and fired the first round with the revolver he thought out loud "I don't remember these having this much recoil and muzzle blast. Same story for the 2nd round but shot #3 was all different. The firearm had become a grenade in his hand: top half of the cylinder was missing, top strap was sheared, total destruction. He gathered his gear and headed back home to his handloading station. When he got there he found his reloading manual still sitting on the bench with weights on it holding the pages open. The top of the pages he had been using for his reference read "45 Colt." And now you know the rest of the story. BTW, this was not the only firearm he overloaded and destroyed with his handloading adventures.

[Thundermaker]

SAAMI specifications are what the industry loads the cartridges to for safety in most all firearms, particularly those the cartridges were originally made for. Yes, there are some exceptions/updates but SAAMI standards/specs are not what certain cartridges can be safely handloaded to in other firearms. The 45 Colt and 45-70 are examples. Consider the 222 Rem and 223 Rem and be safely loaded to US 5.56 pressures when chambered in the firearms (modern actions) that can also handle the 5.56 pressures (not SAAMI standardized). Also, the 303 Brit and 30-40 can be loaded, safely, to higher pressures in rifles such as P14s, M10 Ross's, Siamese Mausers and Ruger SS actions but SAAMI specs for both are held to original specifications for those cartridges.

SAAMI represents the industry not reloaders, so SAAMI specs are, again, what the industry adheres to. SAAMI specifications /specs are also considered as "standards" if any legal litigations come about.


And CUP and PSI still aren't equal.

[M-Tecs]

And CUP and PSI still aren't equal.

And NO ONE is claiming they are. They are very different methods to measure pressure. In the 45/70 28,000 PSI and 28,000 CUP have the same number representation. Currently the same for the 45 Colt at 14,000.

The 45/70 convergence at 28,000 with PSI and CUP has not changed since the mid 70's and possibly longer. My references only goes back to the mid 70s.

Currently that also happens with the 45 Colt at 14,000. At one time the Colt was listed at 14,000 PSI or 15,900 cup.

It is somewhat similar to Fahrenheit and Celsius scales convergence at minus 40 F. That means minus 40 F and minus 40 C represent the same temperature/value. What is different with this verse PSI/CUP is that Fahrenheit and Celsius also have the ability to be directly converted. PSI and CUP not so much

[jreidthompson1]

I'm not aware of any Italian "clones" chambered in .44 Magnum. All of those I've seen are visibly larger in size than a Colt SAA and reproductions thereof.

35W

Uberti's 1873 Cattleman Callahan model is 44 magnum





Sent from my SM-G781V using Tapatalk

[M-Tecs]

Another 44 Mag here

https://www.guns.com/news/2019/02/13/if-cowboys-were-italian-traditions-1873-revolvers-by-pietta-video

https://www.traditionsfirearms.com/product/1873-single-action-revolver-44-mag-4.75-inch-barrel-color-case-hardened-sat73-800

[35 Whelen]

Uberti's 1873 Cattleman Callahan model is 44 magnum





Sent from my SM-G781V using Tapatalk

Right, but I believe it's an 1873 only in name, and has a much larger frame than a traditional 1873.

35W

[45 Dragoon]

Yap, Brian Pearce is probably the best source with documentation and equipment for such. He states the Uberti copies are suitable for 45C +p loads. I've been testing the Uberti open-top platforms ( belt and horse pistols) for use with 21,000 psi loads in 45C as well as 23,000 psi 45acp (+ p's) with conversion cylinders ( not the factory conversions).

Mike

[Dan Cash]

They also chamber them in 44 Magnum.

They also burst a cylinder when fed so-called Ruger level .45 Colt loads.

[45 Dragoon]

They also burst a cylinder when fed so-called Ruger level .45 Colt loads.

You know there is a "range" of "Ruger only" loads? It's not just "a" load. As I posted above, I shoot lower end "RO" loads in open-top platform revolvers with conversion cylinders. I wouldn't attempt "upper end" loads.

Mike

[HWooldridge]

I have an old model Ruger Blackhawk in 45 LC and have fired "upper end" loads out of it (WW296 and 250 gr pill). It's absolutely no fun at all - I don't think it's worth loading anything that hot unless you need to shoot lions, and tigers, and bears, oh my...

[justindad]

I’m a bit apprehensive about the idea that a Uberti can shoot .45 Colt @ 21ksi just because it can shoot .45 ACP at that pressure.
1) Force = Pressure X Area, and the .45 Colt has significantly more surface area around the cylinder of the cartridge.
2) I’ve never broken a pistol, but I’ve read that heavier bullets at the same pressure wear a gun out faster. The .45 Colt tends to use heavier bullets. Recoil & momentum matter, so the heavier bullets matter. Also, Kimber told me not to shoot 180 grain bullets in my K6S because they only tested up to 158 grain bullets.
*
Since Uberti is European, their pistols are tested to the CIP standard, which does give you a little bit of head room over SAAMI.

[Jungle Dave]

I don't like pushing the pressure in my SAA's more than 8 grs Unique and a 250. No sense in pushing more than that.

[Thundermaker]

I have an old model Ruger Blackhawk in 45 LC and have fired "upper end" loads out of it (WW296 and 250 gr pill). It's absolutely no fun at all - I don't think it's worth loading anything that hot unless you need to shoot lions, and tigers, and bears, oh my...

That's what I've found also. Once you get outside the SAA loads, recoil gets miserable real quick.

[DougGuy]

They also burst a cylinder when fed so-called Ruger level .45 Colt loads.

The Uberti 44 magnum is built on a considerably beefier frame and cylinder than the standard SAA. I had one. It's closer to the old original Vaquero in size and thickness of frame and cyinder than the smaller traditional Colt clone SAA.

[lar45]

I’m a bit apprehensive about the idea that a Uberti can shoot .45 Colt @ 21ksi just because it can shoot .45 ACP at that pressure.
1) Force = Pressure X Area, and the .45 Colt has significantly more surface area around the cylinder of the cartridge.
2) I’ve never broken a pistol, but I’ve read that heavier bullets at the same pressure wear a gun out faster. The .45 Colt tends to use heavier bullets. Recoil & momentum matter, so the heavier bullets matter. Also, Kimber told me not to shoot 180 grain bullets in my K6S because they only tested up to 158 grain bullets.
*
Since Uberti is European, their pistols are tested to the CIP standard, which does give you a little bit of head room over SAAMI.

It's the diameter of the case and the thickness of the cylinder walls that comes into play here. Not the length of the cartridge.
http://www.lsstuff.com/pics/misc/hoop-stress.jpg
https://www.engineersedge.com/material_science/hoop-stress.htm

[45 Dragoon]

I’m a bit apprehensive about the idea that a Uberti can shoot .45 Colt @ 21ksi just because it can shoot .45 ACP at that pressure.
1) Force = Pressure X Area, and the .45 Colt has significantly more surface area around the cylinder of the cartridge.
2) I’ve never broken a pistol, but I’ve read that heavier bullets at the same pressure wear a gun out faster. The .45 Colt tends to use heavier bullets. Recoil & momentum matter, so the heavier bullets matter. Also, Kimber told me not to shoot 180 grain bullets in my K6S because they only tested up to 158 grain bullets.
*
Since Uberti is European, their pistols are tested to the CIP standard, which does give you a little bit of head room over SAAMI.

The most destructive "feature" of a single action is the endshake spec. Shooting heavy loads and heavy bullets does exactly the same thing that loose cylinders on open-top revolvers do. The cylinder turns into a slide hammer and beats the revolver unnecessarily.
Imperceptible endshake is best if there's a bushing/ gas ring. In the instance of and open-top with no gas ring, .002" would ( to me) be maximum endshake.

Mike

[35 Whelen]

The most destructive "feature" of a single action is the endshake spec. Shooting heavy loads and heavy bullets does exactly the same thing that loose cylinders on open-top revolvers do. The cylinder turns into a slide hammer and beats the revolver unnecessarily.
Imperceptible endshake is best if there's a bushing/ gas ring. In the instance of and open-top with no gas ring, .002" would ( to me) be maximum endshake.

Mike

If you've ever fired a 45 Colt loaded with a 250-255 gr. bullet over a compressed charge of 3Fg, you'd probably agree that it falls in the "heavy load" category!

35W

[M-Tecs]

Friend has one of Great Western 44 Mags. It was the first 44 Mag that I fired. That was in the early 70's and it appeared to be the same size as the 45 Colt Cattleman that dad owned.

https://greatwesternarmsco.com/calibers/44-magnum/

During that time period the Hawes Western Marshal 44 Mags 1873's were common. They were made in Western Germany by J. P. Sauer and Sohn. A college buddy had one.

[Larry Gibson]

Friend has one of Great Western 44 Mags. It was the first 44 Mag that I fired. That was in the early 70's and it appeared to be the same size as the 45 Colt Cattleman that dad owned.

https://greatwesternarmsco.com/calibers/44-magnum/

During that time period the Hawes Western Marshal 44 Mags 1873's were common. They were made in Western Germany by J. P. Sauer and Sohn. A college buddy had one.

I still have one. Got it for my 21st birthday. I've put thousands of "Keith" loads through it. It shows some wear and tear but I only shoot 44 SPL loads in it any longer.

[45 Dragoon]

If you've ever fired a 45 Colt loaded with a 250-255 gr. bullet over a compressed charge of 3Fg, you'd probably agree that it falls in the "heavy load" category!

35W

Oh yes, it will get your attention for sure!!

Mike

[justindad]

It's the diameter of the case and the thickness of the cylinder walls that comes into play here. Not the length of the cartridge.
http://www.lsstuff.com/pics/misc/hoop-stress.jpg
https://www.engineersedge.com/material_science/hoop-stress.htm

That is partially correct. However, pressure is not the full story.
*
Modeling the complex geometry of a six holed cylinder as a thin walled pressure vessel is a gross oversimplification, because the variable wall thickness violates the 1:20 wall thickness to radius requirement of the thin wall model. The length of the chamber over which the pressure applies is time varying and also precludes the application of the thin wall pressure vessel model, because the thin wall model requires a very long cylinder.
*
Hoop stress cannot explain axially directed frame stretch and endshake growth before the cylinder cracks. Consider what happens when the bullet hits the forcing cone and the case pressure provides your hands with felt recoil - opposite but not quite equal forces. Consider that the .45 Colt uses heavier bullets and roll crimps.
*
If the only failure mode is cylinder rupture without frame stretch, then pressure is adequate. If Uberti SAA clones experience frame stretch before cylinder rupture, then pressure is inadequate and it is bad advice to say a .45 Colt can withstand 21ksi on the basis of .45ACP cylinders.

[lar45]

Pressure = Pressure .
Have you ever seen a picture of a blown cylinder? They always blow the top off, never have I looked at a picture of a blown cylinder where it split front to back.
Roll crimp or taper crimp does not matter. It's chamber pressure and the strength of the material trying to withstand it.
If you don't like the thin walled Pressure vessel equation, try the thick walled version.

[lar45]

313141

[justindad]

You are right that cylinder rupture is caused by pressure, but incorrect to apply static equations to transient events. This transient event does not qualify for quasi-static equilibrium modeling.
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If hoop stress was the only factor then frame strength wouldn’t matter.
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There is more stored potential energy in a .45 Colt load than in a .45 ACP load given the same pressure.
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I’m applying common sense thoughts here, because modeling stresses in this event is not simple. I’m not putting 23ksi Colt loads in my Uberti.

[lar45]

If we are worried about frame stretching, then the forces applied are "Bolt Thrust". Which is the radius of the case, squared, times pi(3.14 roughly), times chamber pressure. pi*R^2*P = bolt thrust
Again, the length of the case does not matter.
Think of this as a hydraulic ram trying to stretch the frame. It doesn't matter if the ram is 1.00" long or 1.5" long. As long as both rams are the same diameter(45acp and 45Colt are pretty close to each other), and have the same internal pressure(23ksi), then both rams will apply the same force.

[Lloyd Smale]

i was always taught that it was case head diameter not case diameter so a 45 colt loaded to the same pressure with the same weight bullet will have more bolt thrust then a 45acp or 44spec. it was one of the main reasons john linebaugh loaded the 500 at a whole lot less pressure then the 475

[lar45]

i was always taught that it was case head diameter not case diameter so a 45 colt loaded to the same pressure with the same weight bullet will have more bolt thrust then a 45acp or 44spec. it was one of the main reasons john linebaugh loaded the 500 at a whole lot less pressure then the 475

Hi Lloyd, are you talking about the base of the case, or the rim diameter?
I have read that it's the base of the case, or the case head, not the rim diameter.
At one of the Linebaugh big bore seminars in Cody, John had a 500 Linebaugh cylinder that someone had overloaded and it had a bulge over one of the chambers.
The 500 L is loaded to lower pressures because the cylinder wall thickness is less than the 475 L.

[justindad]

You cannot rely on static equations to explain transient events.
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Consider differences in felt recoil when pressures are the same. The level of pain in your hand is different, do you really think the stress is the same?

[Lloyd Smale]

Hi Lloyd, are you talking about the base of the case, or the rim diameter?
I have read that it's the base of the case, or the case head, not the rim diameter.
At one of the Linebaugh big bore seminars in Cody, John had a 500 Linebaugh cylinder that someone had overloaded and it had a bulge over one of the chambers.
The 500 L is loaded to lower pressures because the cylinder wall thickness is less than the 475 L.

i know john personaly and my buddy was one of his best friends. i had 4 500s and two of his 475s my buddy has 2 475s 5 500s and a 500 max. We have put thousands of 475 pressure level loads loads throgh all thoe 500s with johns blessing and never had a single problem or even sticky extraction. had to be a real idiot that overloaded it. maybe an extreme overload with unique because i really cant see a faster power even being on the bench when i loaded 500s. lars it is rim diameter. theory is the bigger the rim the more it transferred. where it really comes into play is in large caliber lever guns like the 50 alaskan. bolt thrust would beat them up with those loads that tend to start opening the lever before you wanted it to. lucky for my gun was that those loads made me tap out before the gun did. even when rob applegate built me my marlin 94 in 475. i asked him about loads and he told me that the gun would take the pressures of full power 475s but bolt thrust would beat it up with a steady diet of them

[Frank V]

We can argue how much pressure they’ll stand all day. Why do we want to load them to the point of just before they come apart? I’ve shot the .45 Colt for years & for me, I have found there is very little a .454 dia WFP lead bullet at 830fps won’t reliably do. Penetration almost has to be seen to be believed. This velocity can easily, safely, be reached in a Colt SAA that’s in good condition, with several powders. It’s a load that can be shot a lot & is fun & will do 90% of what a six-gun should be called upon to do.
Thanks.

[M-Tecs]

Bolt thrust and PSI of the case head are not the same. Theoretical bolt thrust is calculated by multiplying the chamber pressure by the internal area of the cartridge head. Actual bolt thrust is reduced by case adherence to the chamber walls with the exception of revolvers since the cylinder is basically free floating.

The PSI of the case head for a 45 Colt will be less than a 45 ACP at the same pressure. Bolt thrust increases as the internal area of the cartridge head increases. Internal areas of the 45 Colt and the 45 ACP are basically the same so bolt thrust will be basically equal.

At the same pressure a 223 Rem. will have less bolt thrust than a .223 Winchester Super Short Magnum.

[lightload]

In a New Vaquero 45 Colt, Ruger advises keeping pressure below certain limits. I agree. But please explain how the above technical discussion applies to the the New Vaquero in 45 Colt.

[lar45]

The new Vaquero in 45 colt can also come with a 45acp cylinder. So if it's safe with 45acp at 21kpsi then it would also be safe to load the 45 colt cylinder to 21kpsi.

[DougGuy]

ALL Ruger single action 45 caliber revolvers are rated for 45ACP+P 23,000psi. Matters not 45 Colt or 45 ACP.

[Lloyd Smale]

We can argue how much pressure they’ll stand all day. Why do we want to load them to the point of just before they come apart? I’ve shot the .45 Colt for years & for me, I have found there is very little a .454 dia WFP lead bullet at 830fps won’t reliably do. Penetration almost has to be seen to be believed. This velocity can easily, safely, be reached in a Colt SAA that’s in good condition, with several powders. It’s a load that can be shot a lot & is fun & will do 90% of what a six-gun should be called upon to do.
Thanks.

sure cant argue with that

[justindad]

If Ruger and and Uberti do not claim 23ksi for these 45 Colt revolvers, then either:
1) they are a bunch of doofuses for under-rating their guns, or
2) the fact that transient events cannot be modeled with static equations matters here.
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I have designed many machines to with stand impacts, shocks, and other transient events. You’d be surprised how many times people tried to use f=m*a to figure the loading in an impact, just to find their designs fail. I hope no one takes advice here over manufacturer’s recommendations and loses their fingers.

[M-Tecs]

If Ruger and and Uberti do not claim 23ksi for these 45 Colt revolvers, then either:
1) they are a bunch of doofuses for under-rating their guns, or
2) the fact that transient events cannot be modeled with static equations matters here.
*
I have designed many machines to with stand impacts, shocks, and other transient events. You’d be surprised how many times people tried to use f=m*a to figure the loading in an impact, just to find their designs fail. I hope no one takes advice here over manufacturer’s recommendations and loses their fingers.

I am not aware of any manufacture that use a specific pressure for rating their firearms. They rate their firearms safe for use with specific cartridges base on SAAMI or C.I.P guidance for that cartridge.

Since there is no SAAMI 45 Colt +P specification all 45 Colt firearms are rate at 14,000 period yet in some instances the same firearm is chambered in the 454 Casull which is a 65,000 PSI cartridge. Depending on the design their firearm might be 100% the same for a 45 Colt and a 454 Casull. In others, the manufacturer may use different materials and/or HT for the 454 Casull.

Per the manufacturer it's safe to fire a 454 Casull at 65,000 PSI yet in the same firearm the manufacturer's position is that it is not recommended or safe firing a 45 Colt at anything above the 14,000 SAAMI rating.

SAAMI recommendations are based on the weakest designs that are still in use. That includes the firearm design and brass designs with the caveat they exclude balloon head and semi-balloon head cases.

It gets even more interesting when modern firearms are chambered in non-rated SAAMI cartridges like the 40-65. At least in some of those instances the manufacturer states blackpowder only.

Knowledge and common sense goes a long way in staying safe.

[Larry Gibson]

I have an Uberti made factory 45 ACP cylinder for my Uberti Evil Roy SA. I've been shooting my standard 45 ACP load which is a 200 gr cast [usually the a Lee 452-200-SWC copy of the H&Gs] over 5 gr Bullseye which runs 18,900 psi +/-. More recently I've been shooting the Lee 452-230-TCs, which run 234 gr fully dressed, over the same 5 gr Bullseye load which give 20,000 psi +/-. My 45 Colt loads with the same two bullets run 14,000 - 18,000 psi.

[M-Tecs]

Larry, are you using the same 5 grains of Bullseye in the 45 Colt also? If so, how do the velocities compare to the 45 ACP?

[Larry Gibson]

No, I use 7.2 gr Bullseye under the 200 gr cast in the 45 Colt which give 14-15,000 psi at 950 fps out of the ER Uberti. Under the 234 gr Lee TC bullet I use 7 gr Bullseye which give 16,700 psi +/- at 902 fps out of the ER Uberti. The 45 ACP 200 gr loads run 890 fps and the 234 gr loads run 840 fps.

[DougGuy]

If Ruger and and Uberti do not claim 23ksi for these 45 Colt revolvers

Ruger won't even admit this about their 45 Colt cylinders or revolvers, regardless of what gun, but they state the SAAMI prescribed 14,000 psi limit. They may not even go as far as quoting the 14,000 psi SAAMI spec, they may only say "factory ammo." That is ALL company policy will allow them to say.

They are well aware of the fact that load data for 45 Colt and their revolvers far exceeds the SAAMI limit.

They WILL freely admit that the guns chambered in 45 ACP are safe with 45 ACP+P ammunition.

The cylinder wall thickness is the same so it's an easy deduction that the 45 Colt cylinder will withstand the same 45 ACP+P pressure as the 45 ACP cylinder.

As mentioned earlier in this thread, it doesn't really matter how long the cylinder is, the pressure on cylinder walls and webs is the same. The danger is the thin area at the bottom of the bolt cuppet. Afaik, this thin area is the same thickness on the Ruger 45 Colt and Ruger 45 ACP cylinders.

[M-Tecs]

No, I use 7.2 gr Bullseye under the 200 gr cast in the 45 Colt which give 14-15,000 psi at 950 fps out of the ER Uberti. Under the 234 gr Lee TC bullet I use 7 gr Bullseye which give 16,700 psi +/- at 902 fps out of the ER Uberti. The 45 ACP 200 gr loads run 890 fps and the 234 gr loads run 840 fps.

Larry thanks for the info. While I have a chrono I have no way to test pressure. I have often wondered how pressures are affected in same caliber cartridges with different case volumes when loaded to the same velocities using the same powder and bullets.

Simplified the question is are there any noticeable differences in pressures at equal velocities between the 45 ACP and the 45 Colt out of the same firearm using the same powder and bullets with the only difference being the increased charge weight to equal the velocities?

My assumption is that even with the increased powder charge the pressures will be lower for the same velocity, however, I have never seen data from an actual test.

[lightload]

Excellent information here. I like the 45 Colt because of its combination of effectiveness with gentle recoil.

[FergusonTO35]

Load manuals usually have a separate segment of de facto .45 Colt +P loads for Ruger/TC/Freedom Arms etc., so there is that. I can't imagine these loads would be published if there was any question that these guns could handle them.

[Larry Gibson]

Larry thanks for the info. While I have a chrono I have no way to test pressure. I have often wondered how pressures are affected in same caliber cartridges with different case volumes when loaded to the same velocities using the same powder and bullets.

Simplified the question is are there any noticeable differences in pressures at equal velocities between the 45 ACP and the 45 Colt out of the same firearm using the same powder and bullets with the only difference being the increased charge weight to equal the velocities?

My assumption is that even with the increased powder charge the pressures will be lower for the same velocity, however, I have never seen data from an actual test.

Basically, the pressures run the same given the same powder/bullets used for the same velocity. The 45 Colt does require more of the powder to achieve the same pressure/velocity of course. Test to test variations can give the 45 Colt the edge and the next test the 45 ACP can have the pressure/velocity edge.

My 45 Colt loads listed above were actually developed to give 1150 fps +/- out of my 20" Uberti M73. I then just accepted that load for use in the Uberti SAs. The 45 ACP load is just my standard M1911 loads for those bullets. Again, just accepted for use in the SAs and my S&W M1917/25.