All Smith N-frames are not created equal?

[Quoheleth]

I was reading Ken Waters' book PET LOADS this morning and was looking at the information on the .41 Magnum and .45 Colt. As I read and compared the data for the two rounds, I realized that he was using this data in comparable Smith & Wessons (with the exception of the Group III .45 data for Ruger/TC Contenders only). Looking at velocity and pressure, the .41 was loaded to velocities were the .45 is leaving off, @ 1100fps. Likewise, pressures are considerably higher in the .41 than the .45.

Conventional wisdom says, "don't try to turn your Smith .45 Colt into a .45 Magnum. If you do, bad things will happen. Yeah, you might get away with it for a few shots, but it's not made for that heavy of loads."

So, why is it that a handloader can crank the .41 Magnum (or, I assume even the .44 Magnum - I didn't look at those pages yet) up that much more than the .45? Is it all in the heat-treating of the gun?

Don't get me wrong - I'm not wanting to turn my 25-5 into a .45 Magnum. I'm just curious as to what is the difference between a 25-5 and a 57 (or even a 29) that allows so much more horsepower?

Q

 

[pendennis]

Part of the reasoning goes to the fact that the heat treatment for the mangum calibers is different than that of the standard calibers. The Models 25-x also have bigger bores. The magnum calibers are at about .420 and .410. The cylinder walls of the magnums are also thicker.

Handloaders who jack up the performance above that of factory ammo, are on their own if they get a kaboom. S&W will politely say, "Sorry", and send you on your way.

"Conventional wisdom", in this case is spot on.

 

[highlander 5]

It's not the frame it's the chamber wall thickness and where the bolt cuts are made. I had a model 25 in 45 Colt years ago and I measured the chamber walls and they where thinner than the walls on my 45 Blackhawks plus the bolt cuts where made on the chamber wall as opposed to Ruger who cut the bolt stop between the chambers. The heat treatment may be different for the magnum class cyinders as well but I won't swear to that. Loads up to 1000 fps should be safe in a model 25,that should do anything you want under normal circumstances. The original black powder load with a 250 gr bullet was supposed to drop a horse in it tracks.

 

[Lucky Derby]

Different heat treatment+more metal in the cylinder.

 

[USSR]

It's not the frame it's the chamber wall thickness and where the bolt cuts are made.

Yep. I load my 25-5 with handloads that tend not to exceed 23k psi. Why 23k psi? Because the 25-2 S&W in .45 ACP uses the same frame and basically has the same size holes in the cylinder, and it will handle .45 ACP +P loads which are SAAMI rated at 23k psi. You can create some pretty potent loads and still stay within 23k psi.

Don

 

[Slamfire]

Different forcing cone angles is another.

 

[CraigC]

Has nothing to do with heat treatment on post-war guns and everything to do with chamber wall thickness and the location of the bolt cuts in the cylinder.

 

[1KPerDay]

It doesn't make sense that they would have a different heat treatment process for each caliber. Does anyone have any evidence that this is the case?

 

[4v50 Gary]

Pendennis wrote:

Part of the reasoning goes to the fact that the heat treatment for the magum calibers is different than that of the standard calibers. The Models 25-x also have bigger bores. The magnum calibers are at about .420 and .410. The cylinder walls of the magnums are also thicker.

He's right. The heat treatment is different. I remember when in the wake of the Dirty Harry movies the M-29 44 Magnum's popularity was such that S&W could not meet demands. To meet consumer demands, gunsmiths were converting M-27 .357 Magnums by reboring the barrel and cylinder. It's not the same as a factory made gun.

 

[rcmodel]

Has nothing to do with heat treatment on post-war guns and everything to do with chamber wall thickness and the location of the bolt cuts in the cylinder.

What he said.

The .357, .41, .44, and .45 N-Frames of that period were all the same strength as far a metal & heat treating.

But there is very little cylinder wall left at the bolt cuts when you bore .45 holes in them.

That is the weak link in the chain in the .45 Cal N-Frames, be it .45 Colt or .45 ACP.

rc

 

[Quoheleth]

The problem isn't the quality of steel but the amount of steel.
Got it.

Again - I am not looking to hotrod my gun and I'm not wanting to destroy it with foolishness. I like loads that are in the 800-900fps range - a nice authoritative bark with just enough recoil to make me smile.

Thanks,
Q

 

[CraigC]

To meet consumer demands, gunsmiths were converting M-27 .357 Magnums by reboring the barrel and cylinder. It's not the same as a factory made gun.

The only issue with this is the shorter cylinder of the model 27. These guns are routinely converted to fancy .44Spl's and the Keith load is often used in them. Strength is a non-issue.

 

[Walkalong]

As USSR posted, there is no reason a 25-5 cannot take .45 ACP pressures as does the 25-2, and that makes the .45 Colt pretty potent. Not .44 Mag potent obviously, but stout enough for many things.

 

[Owen Sparks]

The .41 has much thicker cylinder walls than the .45, that alone is the difference. If you want to hot load the .45 Colt get a Ruger or better yet a Marlin with a 20" barrel if you really want high velocity.

 

[Quoheleth]

Interesting.

I read a little further in PET LOADS on the .45 Colt page this afternoon and was surprised that Waters' #1 reason not to Magnumize the .45 Colt is the strength of the case! His #2 reason had to do with the gun. When he spoke about the gun, his analysis was that posited here - the cylinder walls and notch weaken the cylinder.

Thought it was interesting that #1 reason was the brass.

Q

 

[harmonic]

It doesn't make sense that they would have a different heat treatment process for each caliber. Does anyone have any evidence that this is the case?

That's almost funny that people believe that. The frames were mass produced and then picked at random depending upon which model they were tooling for. It's the same frame for the 29, 28, 27, 25, etc. Then they would stamp the model they were producing. All the frames were manufactured identically.

 

[DWFan]

Check your cylinder throats for uniform diameter and use the proper size bullets. This is a problem area for both the S&W and Ruger. You can load the RCBS 45-270-SAA 270gr SWC to run 1000-1100 fps from your M25.

 

[Walkalong]

Waters' #1 reason not to Magnumize the .45 Colt is the strength of the case!

The case can obviously take it.

 

[CraigC]

Didn't realize Ken Waters was perpetuating that weak case myth as well. T`was the only time ole Elmer was wrong.

 

[Slamfire]

I read a little further in PET LOADS on the .45 Colt page this afternoon and was surprised that Waters' #1 reason not to Magnumize the .45 Colt is the strength of the case! His #2 reason had to do with the gun. When he spoke about the gun, his analysis was that posited here - the cylinder walls and notch weaken the cylinder.

Thought it was interesting that #1 reason was the brass.

Ken Waters does not have a degree in mechanical engineering, materials, or physics, for all the articles he has written he is incapable of asking intelligent questions on structures, strength of materials from industry people who could have set him down the path to enlightenment. Ken Waters has created or perpetuated a number of terms “over bore” being one, “efficient” another, these terms are only useful for creating sound and fury over nothing.

If the brass is the same, if the hardness is the same, if the head and sidewall thickness are the same, than the ultimate and yield will be the same. There will be differences in taper, wall thickness, primer hole size, but all things being equal, the predominate strength issue with cases will be the materials used and the thickness of the case head. The case is simply a gas seal and is not intended to carry load. If the case is not supported it will rupture. Case support is usually the difference between what gun writers call a “weak” case and a “strong” case.

Case support is so important, you see images all the time of blown case heads in Glocks, be it 45 ACP, 9mm, 40 S&W, and the difference between Glocks and other designs which were not having issues is case head support. Or should I say was, because Glock redesigned their barrels to provide better case head support.

It is obvious examining the cylinder wall thickness of a N Frame 44 Magnum and a 45 LC cylinder that the 44 Magnum has thicker walls. Thicker walls means the thicker cylinder will stretch less given the same load, which means the case will stretch less for the same load. There are probably subtle issues with frame flexing that only CAD models would reveal, so I am ignoring those.

For me, the best reason not to attempt to magnumtize the 45 LC has to do with cylinder thickness and the fact we don't know if there is a difference between the cylinder materials and their heat treatment for 45 LC's and 44 Mag's. There is no reason to assume that they are the same.

 

[harmonic]

There is no reason to assume that they are the same.

Yes there is. Smith and Wesson isn't going to have two heat treating procedures when one will do. They'll just heat the 45 the same way as the 44 and 41 at half the cost.

 

[Slamfire]

Yes there is. Smith and Wesson isn't going to have two heat treating procedures when one will do. They'll just heat the 45 the same way as the 44 and 41 at half the cost.

Call them up and ask them. Then tell us what they say.

 

[USSR]

Didn't realize Ken Waters was perpetuating that weak case myth as well. T`was the only time ole Elmer was wrong.

Actually, Elmer wasn't wrong - when he initially said it. Prior to the 1950's, .45 Colt brass was balloon head brass, and was weak. For about the last 60 years, .45 Colt brass is no different than any other modern handgun brass. Where some of these writers run into problems is, they take things that are said or written out of the context of the day and age in which they were said.

Don

 

[CraigC]

Elmer Keith did not just say that the cases were weak. He blamed a "weak case" for the destruction of a milsurp 1st generation blackpowder Colt. It wasn't the case that let go, it was the sixgun with his 300gr cutdown .45-90 bullet over a caseful of blackpowder that let go. Keith was wrong and the myth was born.

 

[USSR]

CraigC,

He blamed a weak case in a case design that had structural deficiencies. All balloon head cases are by design weak. That's why they quit making them.

Don