Case Strength - .38 Spl/+P vs .357 Mag

Status
Not open for further replies.

NoAlibi

Member
Joined
Jun 22, 2009
Messages
500
Location
Boca Raton, Florida
It’s common knowledge that you can fire a .38 Spl & a .38 Spl +P round in a .357 Mag revolver. I was curious if the first two cases mentioned are strong enough to take a .357 Mag loading and would it be safe to shoot in a .357 Mag revolver?

I would also think that the shorter case would be less accurate because the bullet would have to take a longer jump to the rifling. Just wondering…your thoughts?

PS - On second thought I think that even if you can do it, it would not be a good idea. There is a possibility that someone might inadvertently try to fire rounds loaded this way an think they would be okay to shoot in a gun chambered for a .38 Spl. So let’s leave this question as only can it be done sort of thing.
 
Last edited:
The .357 Magnum started out as the .38/44 load using .38 Special brass in the S&W N Frames. The only reason they lengthened the case was so that these heavy loads couldn't be used in lightweight frame revolvers.

Don
 
They are probably strong enough, but they are not long enough.
Using a normal .357 powder charge weight in a smaller .38 Spl case would result in over the top unsafe pressure.

Years ago, gun writers like Elmer Keith and Skeeter Skelton regularly published high performance .357 Mag loads they used in .38 brass.

Also years ago, there were .38/44 HV loads that were loaded in .38 Spl cases, but gave very nearly .357 Mag performance in large frame Colts & S&W's.

But these are kinder gentler days we live in now.

As for accuracy?
Years ago our Army AMU unit ran some tests with .38 Spl Match wadcutter ammo in a M19 .357 Revolver vis a K-38 revolver in a Ransom Rest.
There was in fact a measurable differance in accuracy, but not enough to matter to you, or I, or any other normal pistol shot. And it could also have been just a differance in the two guns we tested?

The major problem I see with what you are suggesting is keeping those loads out of .38 Spl guns.
Despite your best intentions & markings, sooner or later somebody is going to find or inheret some of your super hot loads and blow up an old or small frame .38 Special.

rc
 
rcmodel - Already agreed. I guess you didn't see my "PS" posted at 1:22 PM while you were composing your response. This is for hypothetical purposes only and surely should NOT be done.....Doc
 
I think it is a bad idea to load .38 Spl +P+ brass to .357 levels whether the brass can take it or not. If they mistakenly get fired in a .38 Spl gun it would be very dangerous. Heck, you could get hit by a beer truck on the way home and your kids would not know not to shoot them in a .38.

attachment.php
 
Walkalong -We're all in agreement that this would be a bad idea, however, my question still has not be answered definitively.

Are the those cases as strong as a .357 Mag case, i.e., can they be loaded to the same pressure levels?

BTW, a Mitutoyo ball mic...top of the line, very nice! ;)

PS - The odds of me getting run over by a beer truck are exponentially less than getting shot trying to hijack a stocked-up one.....Doc :evil:
 
Walkalong -We're all in agreement that this would be a bad idea, however, my question still has not be answered definitively.

Are the those cases as strong as a .357 Mag case, i.e., can they be loaded to the same pressure levels?

Again:
The .357 Magnum started out as the .38/44 load using .38 Special brass in the S&W N Frames. The only reason they lengthened the case was so that these heavy loads couldn't be used in lightweight frame revolvers.

Short answer: Yes.

Don
 
I fired a case full of +P 38 Specials in my M66-2.

And it took a lot of work to remove the lead ring that developed in each cylinder. The lead ring made it difficult to eject 357 cases, as they fireformed around the ring.

So yes, you can shoot 38 brass in a 357 cylinder. But you may not want to, long term.

reducedM66-2leftsideDSCN5035.jpg
 
As Walkalong so aptly points out with his photo of the measurements of the two cases, the .38 Special case is designed to contain roughly 20,000 psi+/-, while the .357 Magnum case is designed to contain roughly 40,000 psi+/-. Those are the levels they're usually proofed at, 10% over maximum for the caliber.

In my opinion, the .38 Special case isn't designed to contain the pressures of the .357 Magnum, and shouldn't be loaded to those levels. The magnum case is thicker in the web and walls than the .38 case, so it better withstands the higher pressures.

Oh, I know some people do it and get away with it, but that doesn't mean it's a good idea. Heck, when I first started in Law Enforcement in 1969, we had patrol cars that would bury a 140 mph speedometer, but the nylon tires we had at the time were only rated at about 85 mph. I buried the speedometer numerous times in pursuits, and got away with it, but I also blew 3 different tires at over 120 mph at different times.........

The same thing applies to overloading a case, it's going to eventually let go on you.

Hope this helps.

Fred
 
USSR - The NRA publication “Handloading” (c1981) on page 246 states that the 38-44 was a 1930s high pressure version of the .38 Spl comparable to modern +P ammunition and was only to be used in heavy framed revolvers. Remember this is the NRA's data, so don’t shoot the messenger. If you have any published data about the 38-44 or .38 Spl that is different than the above please let me know where I can find it.

If this publication is correct then it should be noted that the maximum product average chamber pressure of the +P cartridge is 22,400 cup which is about less than half than that of a .357 Mag, so this doesn’t really give me a definitive answer of what kind of pressure a .38 Spl case can take. More on the case in a moment…

Reloader Fred - The NRA publication “Handloading” (c1981) in the “Standard Cartridge and Chamber Dimensions” on page 296 & 298 shows the .38 Spl and the .357 Mag cases to be identical, including the wall and web thickness (.200“) with the exception of the length. The .357 case is .135” longer.

However, this publication nor any of the many other reloading books and manuals I have ever alludes the to metallurgy of the case.
 
From John Taffin:

Keith designed a series of bullets for the Lyman/Ideal Corporation that, with their distinctive semi-wadcutter shape, have come to be known simply as Keith bullets. Along with these bullets, Elmer came up with what have come to be known as the Keith loads. Some of these have been around for nearly sixty years and have still not been improved upon. The Keith loads are as follows:

.38 SPECIAL: For use in heavy-framed guns which today exist only as .357 Magnums, the Keith Lyman 173 grain bullet #358429 over 13.5 grains of #2400 with .38 Special brass. This load goes over 1400 fps. from my 8 3/8" Model 27 and is the most accurate load I have found for it. It will still go 1200+ fps. from a 3 1/2" Model 27 and makes an excellent small game load and defensive load.

Elmer would have laughed at what are today called .38 Special +P loads. His .38 Special loads were the equivalent velocity and pressure-wise of current .357 Magnum loads. So, the brass is up for it, but as previously mentioned, it is not really a good idea if the cartridge could possibly end up in a small frame .38 Special revolver. Ironically, the above load is exactly what I use in a .357 Magnum case, and it is listed in the Lyman 49th Edition manual as a Max load in .357 Magnum.

Don
 
NoAlibi
Regardlessof what the NRA book says about the differances.

Just set a .38 Spl case and a .357 mag case down side by side and look down inside them near the flash hole.

If that doesn't convence you the .357 mag case has a thicker web?
Trim one to the exact same length as the .38 Spl case and weigh them both.

Now, do you believe it?

rc
 
I have friends that load the .38 spl to mag levels with no problems reported. I have never done it because I own a few .38 spl handguns and don't want to risk ruining them.

So yes the spl case can take it but do you really want to do that?
 
NoAlibi,

Look again at Walkalong's picture and compare the two cases. The .357 Magnum is built heavier, and I've found that to be true with all domestic brands. You can even feel the difference when sizing the two different cases. The .38 Special cases glide through the sizing die, however the .357 Magnum cases require a little extra effort, and it's not the length causing it, it's the thickness of the walls.

Hope this helps.

Fred
 
What occurs to me as I read this thread is not would it be safe, but why would one want to do it?

Shooting really high pressure .38s from a .357 chamber leaves a crud ring that will take a while to fully remove, time that probably exceeds in value the extra cost of using real .357 brass for the same loading pressure.
 
joed & beatledog7 - The efficacy and wisdom of loading the .38 Spl cases to .357 Mag levels is already a foregone conclusion. This exercise is to determine the ability of the .38 Spl case to withstand magnum pressures - nothing more.

USSR, ReloaderFred & rcmodel - I’m going to take rcmodel’s advice to trim and weigh a .357 Mag case and compare the weight to a .38 Spl case, then I’m going to measure the dimensions of the cases myself and make the comparison. I’m taking the better-half to town today and when I get home in the evening I’ll do the deed and get back to y’all…..Doc
 
Yes. But things like flattened/cratered primers and difficult extraction will be an issue before the case itself fails.
 
I don't think this was mentioned but if it was I'm sorry for repeating.

If you load both cases with the same charge the pressures in the .38 Special case will be higher because of the limited case space provided by the smaller case. These pressures can be excessive and even dangerous depending on which powders you use.
 
I reload .357 wadcutter loads in .38 Special brass (don't worry, they are too long to chamber in a .38 Special if someone ignores the warning label on the box) and I haven't noticed any problem with case life. They are loaded to about 30000 psi.

I do this so I don't have to readjust my crimp die and my powder drop linkage.
 
I think RC really said better than can be further elaborated, but I'll throw in my two cents any way.
The real problem is in fact the strenght of the firearm considered. The case is not a major factor in whether a pressure range can be tollerated, but whether the frame can withstand around double the pressures produced by .357 mag. performance. The difference in case length between the mag. and special in minima,l and was originally developed like that to prevent inadvertantly shooting a mag. from a special cylinder.
Would you think a comparitively think walled case such as the 7 mag, .270, 30-06 and so on are strong enough to support the 50-60 psi loads that are run through them? Of course not, it's the chamber that provides the necessary support to maintain the integrity of the brass, not the other way around.
 
The case web of the 357 mag is thicker than the case web of the 38 special, but I think they both flow somewhere around 100,000 psi. The primer will pierce way before that.

And the cases will stick way before the primer should pierce.

With fast powder I can usually split the cylinder and half the time break the top strap on 38 specials before that.

So the case strength does not make much difference.
 
Brass is weak, its the cylinder, chamber, gun design that needs to be strong....To support the weak brass;)
 
Hey there Clark. I've noticed for some time now that you seem to enjoy deliberatly blowing up guns. Do you test for someone, or just enjoy seeing what certain firearms can handle, just curious. I'm regularly entertained by your posts, and I also pick up some good information regarding out side the box maximums, being that I like to load at the upper end of data.
Merry Christmas!
GS
 
Hey there Clark. I've noticed for some time now that you seem to enjoy deliberatly blowing up guns. Do you test for someone, or just enjoy seeing what certain firearms can handle, just curious. I'm regularly entertained by your posts, and I also pick up some good information regarding out side the box maximums, being that I like to load at the upper end of data.
Merry Christmas!
GS
You may enjoy Clark's posts bit I for one feel he's dangerous. Sure the regulars know his data is off the wall but what about the new guys or the lurkers who never post and just come by. I think he's dangerous and should not be making the posts he does.
 
I agree.

This post from yesterday is but one example.
http://www.thehighroad.org/showpost.php?p=7805402&postcount=12

Quotes from 10 Speer manuals on .44 Mag max loads.
A few from the 50's, 60's and 70's listing a 23.0 MAX.
And everything after 1974 is lower.

In 1979 Speer changed from mostly jacketed bullets to mostly plated Gold Dot's & TMJ's, which use less powder.

Then to suggest people just ignore the manuals and use 24.0 grains with no disclaimer or warning to newbies?

Not good.

rc
 
Status
Not open for further replies.
Back
Top