+P Through a Model 12: THE TEST...is done!!!!

[chief38]

Osprey,
I am very interested in your test results. My prediction however is that after 1000 rounds your model 12 will be just fine. The modern +P ammo is just not that hot! I would venture to say that the test loads S & W puts through the guns are a lot hotter than any +P we could buy. I have shot an older model 60 (no dash #) with plenty of 158 grain +P hollow point semi wadcuters, with no ill effect. The earlier model 60's like mine were not officially rated for use with +P ammo, but like I said, I have not seen any adverse effects on mine. I think this is a very worthwhile project!

 

[bmcgilvray]

Hey Erich; Just returned home for the weekend and am trying to catch up on reading the good forums.

In my view the +P 158 grain SWC-HP offers a small but worthwhile gain in terminal performance. Don't have any use for lighter bullet +P loads. None of it will hurt the revolver.

 

[budrichard]

"I am no engineer, but it seems improbable to me that a manufacturer as prestigous as S&W would design a weapon where the margins of safety and service life would be significantly affected by the difference in standard and +P pressures - within reason, of course. But, as I said, I am no engineer and certainly have nothing to base my opinion on - other than my own, very limited practices. It will be interesting to see what your test proves."

The S&W model 12 was NOT designed for +P for the simple reason that the +P specification did not exist at the time of manufacture.
On the other hand, I AM an Engineer with Graduate study in Metalurgy.
BTW, be aware that your 'test' will only be a one time data point and the results should not be used to predict the future for similar firearms. Frankly to subject ANY product where failure can lead to injury, to tests that exceed the design specifications without the manufactures certified approval is foolhardy. -Dick

 

[Osprey]

The Log has been updated with cylinder window measurements...

 

[BobK]

Osprey, If I read Dick's responce correctly.......you're gonna have to test alot more M-12's, to reach any general conclusions. You need to test ,at least,a dozen guns!!!

Bob

 

[Osprey]

Originally posted by BobK:
Osprey, If I read Dick's responce correctly.......you're gonna have to test alot more M-12's, to reach any general conclusions. You need to test ,at least,a dozen guns!!!
Bob

I have <STRIKE>three</STRIKE> two M12s...the -2 we're testing; <STRIKE>a nickle -3</STRIKE>; and a dash nothing. I'm 1/4 of the way there, Bob.

.... Osprey

 

[budrichard]

To further clarify my thoughts, I think that the likely hood of a catastrophic failure is minimal, more likely the firearm will go out of tune first and evetually cracks will be found in the frame, since these are the steel cylinder guns, cylinder probablity failure is minimum. In terms of Hazards Analysis, this type would be termed: Low Probability, High Consequence, sort of like flying on an airplane. Certainly if we did not attach value to this combination, designing and manufacturing an airplane could be much cheaper and consequently ticket prices would decline. But as a society,we do attach value to these events. In terms of what your testing will discover or what information it will lead to, unless properly documented, not much. My suggestion, if you really intend to do this, is to contact a Metalurgy Department at a University and determine if someone with a spare Graduate Student, would be willing to assist. A paper could be then end result and then your testing would yield some properly documented results. I am interested in an academic way, but don't want to be part of anyone being injured.
There is a guy who publishes articles, in the Double Gun Journal and performs just the sort of thing you are comtemplating on old doubles without any Professional credentials or Academic Training. All the old (I guess old in age and shooting old guns!) double shooters use his articles to make themselves feel better about shooting all those old doubles with modern ammunition but the old doubles keep failing anyway. I use this an example of where your testing might be headed.-Dick

 

[Phideaux]

Moondawg, Amen!

 

[remat457]

Originally posted by budrichard:
In terms of what your testing will discover or what information it will lead to, unless properly documented, not much....A paper could be then end result and then your testing would yield some properly documented results.

Huh?

I am interested in the results! Kudos to Osprey!

A "properly documented paper" written with the help of a University T.A. holds no interest to me (actually I would find it less credible).

 

[Osprey]

The log has been updated. Please see the second entry on page 1.

Cheers....

sprey

 

[M29since14]

In terms of what your testing will discover or what information it will lead to, unless properly documented, not much.

Of course, and even if properly documented, still "not much." It only applies to the single weapon he is testing. It's a simple field test, much like Elmer Keith's those many years ago. I don't see that it is meant to be the basis for conclusions about metallurgy, design, engineering, etc., across the whole population of revolvers of that type that S&W has produced. I don't think that is the man's intent. But that doesn't mean the test is not interesting and worthwhile to us, as hobbyists, does it?

If someone with the necessary expertise would care to volunteer to develop a testing procedure that would satisfy the type of requirements necessary for a formal scientific study, I don't think many members of this forum could afford it - or be interested enough to read the necessarily technical, detailed report.

It's a hobbyist's attempt to satisfy his own curiosity, and to let his fellow hobbyists know what he found. Nothing more. My ramblings that you quoted were just that - ramblings. (As can plainly be seen, I disqualified myself as any sort of authority before the rambling began.)

I found the mention of the airplane very interesting, since in my own mind, I would liken the chances of Osprey being injured by a catastrophic failure in the course of his test as directly comparable to being injured in an aircraft accident, or less - and yes, still more hobbyist's "ramblings!"

 

[Gearhead Jim]

Many years ago, NYPD switched from standard pressure .38 to +P .38. They noticed that even the steel K frames wore out a little more quickly with the +P, but it was not a big deal. I'm guesing that your M-12 will be doing fine after 1k of +P.

Enjoy your shooting!

 

[photoman]

Originally posted by budrichard:
The S&W model 12 was NOT designed for +P for the simple reason that the +P specification did not exist at the time of manufacture.
On the other hand, I AM an Engineer with Graduate study in Metalurgy.
BTW, be aware that your 'test' will only be a one time data point and the results should not be used to predict the future for similar firearms. Frankly to subject ANY product where failure can lead to injury, to tests that exceed the design specifications without the manufactures certified approval is foolhardy. -Dick

A one time data point is all it takes to debunk this silly myth.

The myth being, and I've heard it MANY times, "If you shoot +P's in <span class="ev_code_RED">a</span> Model 12, it will either (1) blow up (2) stretch beyond use or (3) crack."

So...if we see this Model 12 survive many rounds of +P with no adversity, we can conclude that the myth is just that, a myth.

 

[Osprey]

I'll take "The Word" of real men like Elmer Keith, Bill Jordan, Skeeter Skelton...and Osprey...about what has worked in their guns under real life condtions.

I couldn't agree with you more.... Osprey

BTW, I picked up another 200 rounds of +P today at the VGCA gunshow in PW County, VA.

 

[M29since14]

No comments from Osprey since 9/22, but we can pass over that and will assume he is still alive and has both hands and all fingers.

Last evening I was looking up some info on 945s in the PC section of SCSW3. I happened to notice the picture of the "Ultralight 442" on page 352. What follows is a quotation from the description printed there, and I take the liberty to use it, but of course give credit to the authors Supica & Nahas. (Hopefully they will not take me to task. For those of you who don't own this book, it really is an excellent reference and any S&W man should have one.)

"...a few Model 442s with an aluminum alloy cylinder were made for the U.S. Secret Service as prototypes... These cylinders passed the 5000-round test using +P ammo with no failures."



Well, maybe this shouldn't be an at all, and of course it speaks only for the cylinder, not the frame, or the whole weapon. Nevertheless, I found this pretty interesting. This would be considerably in excess of what I have heard, from many years ago, that S&W considered the service life of airweight J-frame .38 Specials to be a minimum of 2,000 rounds (presumably with non-+P ammo, since it was not made in that era).

 

[M29since14]

Is it becasue of better alloys used in todays guns

S&W do state that the number of guns made was very small - no production run was made. It is possible S&W used a special alloy, but, even for a customer as prestigous as the U. S. Secret Service, I doubt they would be able to pull a rabbit from their hat that defied well understood metallurgy at that time (1997 was given as the date).

Whether present day +P ammunition generates a level of external ballistic performance we judge to be "watered down," if it generates +P pressures, it is still going to subject the gun to increased wear and tear. It would be helpful to KNOW if the +P ammunition used actually generates +P pressures, but pressure testing ammunition from a major manufacturer definitely would take this test beyond the nature of Osprey's practical, "let's see" type of field test.

 

[Art Doc]

Fellow on another forum tested some +P 38s in various media and none expanded. I have heard about newer bullets being designed to open at lower velocitis but he got zero expansion at 850-900 FPS.

I still consider factory +P to be far too mild for me use for SD. I have much more confidence in my 125/1150 loads.

 

[stiab]

Several of the thoughts expressed on this forum draw a direct relationship between increase/decrease in velocity and increase/decrease in pressure. While they are related, it is not a direct one for one relationship, and a increase of 5% (to pick a number) in velocity requires more than a 5% increase in pressure. If you were to graph the relationship, it would not be a straight line. It is not correct to assume that a small increase in velocity requires an equally small increase in pressure. If I am wrong about this, please correct me.

 

[M29since14]

It is not correct to assume that a small increase in velocity requires an equally small increase in pressure. If I am wrong about this, please correct me.

Not sure what your point is here, but of course that is my understanding too.

Perhaps more interesting would be the question of variations in external ballistic performance of +P rounds that are of equivalent pressure, and how they affect service life of the weapon. I suspect these loads subject the weapon to stress considerably greater than another +P pressure load of less performance. Anyone care to theorize on that?

Ex.: Any handloader has seen how different propellants yield radically different velocities with similar pressures.

I am just using theoretical numbers taken from thin air, but lets say in a gun like a .38 Special revolver, with loads assembled with identical components except for the propellant, one load yeilds 800 FPS velocity and one load yields 975 FPS. BOTH GENERATE THE SAME PRESSURE IN TESTING. How much more wear and tear on the weapon, if any, might one see with the higher speed load, even though pressures are the same? I have been curious about this for most of my adult life and of course it is one of those thing probably almost impossible to draw any logical conclusions about, because of the huge number of variables. But operating on the theory that there is a difference and it may be substantial, I invariably try to use slow-burning powders for my handloads as much as I can.

Don Quixote is alive and well.

 

[stiab]

BOTH GENERATE THE SAME PRESSURE IN TESTING. How much more wear and tear on the weapon, if any, might one see with the higher speed load, even though pressures are the same?

I'm not an expert on this subject, but I think someone answered this question in an earlier +P thread, and I'll try to repeat what they said: If you were to graph (there I go with graphs again) the pressure of the lower velocity load it would probably be shaped like a mountain with a sharp peak, with rise and decent to the top pressure causing a steep slope on both sides of the mountain. The higher velocity load would graph like a mountain with a plateau at the top, maintaining the same maxium pressure for a longer period. Although the max pressure reached was the same, it lasted longer in the higher velocity load, and probably provided a little more wear and tear on the gun. I think I said this correctly, but maybe not.