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Old June 3, 2005, 01:09 PM   #1
YosemiteSam357
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.357 mag

I have a question regarding various .357 mag loads. I think I have the answer, but wanted to run it by the experts.

I'm told that damage can be done to K framed S&Ws (and other light framed guns) by using 125gr .357 mag loads, as the guns were originally developed when 158gr was the load of the day. The argument is that the gun wasn't designed for the higher pressure & recoil of the 125gr. load, and both flame/gas cutting and frame stretching can result.

What I don't understand is that, when fired, the 158gr load seems to deliver quite a stronger kick than the 125gr load. This is consistent with my experience with other calibers: a 230gr load in .45ACP kicks quite a bit more than the 185gr load. If this kick (felt recoil) is so much stronger, how can the 125gr .357 load exert more strain on the gun than the 158gr load? I can understand the gas cutting angle, as the 125gr load likely has higher pressure, but why would there be a frame battering/stretching issue with a lighter bullet?

Or is it that the 125gr .357 round is specifically loaded "heavier" than the 158gr? On vendor sites where I've seen load data (Remington, Winchester), it appears their 158gr loads are more similar to their 110gr loadings, where the 125gr loading is considerably stronger than both, in both velocity and energy.

Can anyone clear this up for me? Just trying to learn!

Thanks in advance,

-- Sam
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Old June 3, 2005, 01:32 PM   #2
Webleywielder
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S&W K frame battering by .357mag

I think the problem with K frames was recognized long before 125gr HPs became more commonly used than 158gr SPs. So I don't think gas cutting from 125s was the first issue people had with durability. It is my understanding that nobody ever expected people to shoot large quantities of .357mag in K frames because most training would be with .38Spl. Forty years ago we didn't have anywhere near as many people individually shooting thousands of rounds a year as we do now. The level of participation in shooting sports where power is a critical factor just did not exist. In the salad days of the .357mag K frame low powered PPC was the king of the hill.

A S&W K frame .357mag reminds me of a stock 4WD pickup and a S&W N frame .357mag reminds me of a 4WD pickup setup for the Baja 1000. Nothing wrong with the K if you are willing to use it at maximum capacity infrequently.
By the way, a J frame .357 is a light weight race car with an engine pushed to such extreme R.P.M. that it has to be rebuilt after almost every race.


"In a world devoid of semiautomatics, a properly set-up Webley is the ultimate full-size self-defense handgun."
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Old June 4, 2005, 02:12 AM   #3
Bullet94
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I believe the K frames were designed for 38 Specials 17,000 psi. When loading 357 in K frames the pressures reach 35,000 psi. This difference was or is harder on K frames, plus the flame/gas cutting when using 125gr 357’s is more.

YosemiteSam357 Quote -
“I can understand the gas cutting angle, as the 125gr load likely has higher pressure, but why would there be a frame battering/stretching issue with a lighter bullet?”

The pressures between 125gr bullets and 158gr bullets are the same 35,000 psi. I believe the difference is that the lighter bullets (125gr) need more powder than the heavier bullets consequently higher temperatures. Higher temperatures with faster bullet speeds are probably more harmful than the slower, lower temperature 158gr, but I’m no expert.


The recoil for the 125gr 357 MAX load with the fastest fps is approximately 10% more than the 158gr 357 MAX load with the fastest fps, both loaded with H110 powder. Here is a link to figure recoil.

http://www.travellercentral.com/rules/ke.html


Here is a link to show fps and cup –

http://www.hodgdon.com/data/pistol/357mag.php
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Last edited by Bullet94; June 4, 2005 at 02:57 AM.
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Old June 4, 2005, 03:30 PM   #4
HSMITH
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The whole story about K-frames being weak is an overblown farce. It just isn't so. Get one, put a couple thousand dollars worth of ammo through it and see for yourself.
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Old June 4, 2005, 06:23 PM   #5
YosemiteSam357
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I have a nice nickel p&r 4" model 19. That's why I was asking -- I don't want to beat it to death. I've read that 158gr loads are OK some of the time, but you don't want to shoot a steady diet of them, and should avoid the 125gr loads altogether. I was just trying to figure out where the cheaper, more readily available (commercial) 110gr loads fit in.

-- Sam
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Old June 4, 2005, 06:31 PM   #6
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If I hadda K-frame (again)

Cheap ammo = 38 Specials........gun'll last forever 'n some........
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Old June 5, 2005, 02:02 AM   #7
BillCA
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Hi Sam,

I haven't gotten to the root of this either (i.e. an expert opinion from S&W). But here's what I've learned in rooting around on the subject.

The K-Frame .357 barrel is somewhat thicker than the .38 Special barrel. As a consequence, the .357 barrel has a "flat spot" at the bottom of the barrel/forcing cone to allow it to fit in the K-frame barrel opening. As most engineers will tell you, anytime you take a circular shape and flatten one side of it, you'll introduce potential stress points. The 2nd-Generation 2-piece barrel construction seems to have resolved this issue (at least on my M66-7). Word I hear is that the K-frame will continue but in .38 special only guns while all .357 Magnums will be on the L-Frame.

During the 50's and through the 70's, the Model 19/66 were used by thousands of police officers. While most carried .357 Magnum loads in their guns, most of the practice and qualifications were done with .38 Special ammo. In some cases it was a 148gr Match Wadcutter - very easy on the gun. But seldom did officers fire a LOT of .357 ammo through their guns. Civilians did, though. For hunting, target and self-defense practice. Some agencies started requiring officers to qualify with duty ammo in the 70's and the use of .357 ammo when up. So did throat erosion and in some cases the forcing cones began to show stress cracks.

158gr, 125gr and 110gr ammo -- Also in the 1970's a guy named Lee Juras started producing .357 Magnum hollowpoints of 125gr and 110gr weights that could be pushed to higher velocities compared to the standard 158gr loads. This started the company Super-Vel which had the fastest, hottest "factory" loads available for some years. The fast moving bullets coupled with excess flash-boom of the Super-Vel started wearing out guns. It became well known even then the S&W K-Frames could be "shot out" by over-use of Super-Vel ammo.

In the 80's we saw move factory development of high-speed "lightweight" bullets -- essentially an embracing of Super-Vel's concept that high speed light bullets were still viable for defensive shooting. The problem of a growing number of S&W's with barrel problems came about because of 3 things, and these are my OPINIONs, not gospel.

1. Use of the 110gr and 125gr .357 Magnum loads increased.
With the major manufacturers bringing out "bargain" lines of ammo to keep production units up (thus helping to offset costs of their "premium" ammo), more people could afford to buy .357 Magnum ammo for "range fodder".

2. Sales to many uninitiated shooters - we've seen the growth of shooting, not for sport, but for defense. Plus the traditional linkage of parent-child indoctrination has been broken for most new shooters. It used to be (when I was a kid) there were at least two active shooters on your local block. You'd ask a thousand questions and learn, before your father took you out to the range for the first time. This is where many of use learned to use .38's in the .357 Magnum for practice and shoot "a few" magnums for sighting in before leaving the range. Today, many new shooters use .357 Magnums ALL the time - that macho big-boom thing maybe -- which can wear guns down faster.

3. The popularity of .38 +P ammo - there are a lot of shooters practicing with +P ammo. While the .357 can handle the pressures of .38 +P ammo just fine, it's extra wear & tear on the gun during practice. Couple this with lightweight (110gr) JHPs repeatedly hitting a hot forcing cone at high speed and the stresses add up.

I've decided to use standard pressure .38 specials in most of my J and K framed S&W's for practice. When shooting carry/defense ammo, I let the gun cool down between cylinder fulls. My J-Frame 649 heats up very quickly with WW-USA 125gr JSP .357 ammo. After 10 rounds the cylinder & barrel are too hot to touch! I've purchased my last box of 110gr ammo too. If it's hard on the gun I can adjust to a 125gr round for occasional use.

For practicing your draw & aim (or present & aim at ranges that prohibit holster work) use a mild load like the 148gr Match wadcutters until you are satisfied. For defensive practice, use 158gr LSWC or JSWC ammo in standard pressures. Once you're happy with that, sending 18 or 20 rounds of premium carry ammo down range to adjust your point of aim is probably fine.

Sorry this was so verbose.
But those who know me will tell you I was vaccinated with a phonograph needle!
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Old June 5, 2005, 03:14 AM   #8
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Part of the problem was that ammomakers were using faster burning powders that also produce extrememly high flame temperature (i.e. W-231). Slow powders like H-110 and W-296 will far exceed the velocity of factory ammo, but factory was specifically built for 4" revolvers with the 125 Gr. JHP and police holsters in mind. 158 gr. JHP's are never loaded above 35,000 PSI and neither is the 125, but back before some of the excellent powders we have today existed, well pickens were slimmer and the 158 was not intended as a police load. The original pressure spec of the .357 Magnum was 46,000 CUP and in today's PSI system used by SAAMI, it would be around 50,000 PSI. It just isn't necessary to for the 125 gr. JHP. The route the factories took with faster burners to achieve the supposed 1450 FPS from a 4" barrel made a pretty "HOT" situation for the model 19, or any other .357 Magnum. Load it with a slow magnum powder and you can increase velocity by almost 200 FPS. Problem is, and irregardless of someones personal oppinion about flash, in War and police or any self defense scenario, it's just not a good idea and if you load a 125 gr. JHP in the .357 magnum, you'll need 6" of barrel to achieve it. So, the idea was to use a lower flash powder and increase pressure of what today would be considered inappropriate for the load, so it would cover all the bases in a 4" barrel.

Trying to give a synopsis without it becoming a disertation, but for those that recall my previous thoughts on the subject, you will see the next comment coming. Use a powder faster by one category than the slow magnums and if you want to keep flash down, that means a Ball Powder. Today, we have some very good choices that just weren't available in the past. These are what I would term in the 7-8 speed range, like VV 3N37, AA #7, N-350, Ramshot True Blue and I haven't tried it, but since VV 3N38 was developed for Lapua's proprietary .38 Super Lapua which is nothing more than the .38 Super with a heavier constructed case without going to the extreme of the 9 X 23 and the pressure associated with it to achieve similar velocity, 3N38 should be an outstanding powder for .357 defense loads and 1450-1500 FPS is easily obatainable without temperature and flash problems that can be associated with extremes from the diametrically opposed extremse of W-231/Unique on one hand to H-110/W-296 at the other extreme.

I may be perceived as an arrogant ass, by some here, but I have put some time in, testing this hypotesis and I consider it more than that now and will take it one step further with the permission of Johnny Guest and the absolute understanding that everyone reading this understands the potential danger of working with a Non-Saami Spec cartridge. I trim .357 Magnum (NOT .38 Special +P) brass to .38 Sp. length and load it in the 35,000 PSI Range and there are several reasons for doing this other than being insane. First, Smiths with barrels under 3", use the short ejection rod and if you have been around long enough, no doubt you have heard of extraction/ejection problems. Add 7 shot revolvers to the mix and if you really want to see Sturm step out into space-time continuum, all you have to do is ask me about resonant frequency, because I design sound systems, among other things for a living, and a thin walled cylinder adds peramaters that few outside of a physicist trained in ballistics (not many) would even comprehend. Ever see someone ask about the pitch of a .357 Magnum round loaded to high pressure? It is the highest frequency round that I'm aware of, but I haven't taken the .454 Casull to the extreme, but I suspect it will scream like Ian Gillan of Deep Purple fame. The same powders I mentioned before, work! I have used 3N37 extensively and Factory Magnum velocity which is actually less than 1400 FPS from a 4" barrel, can be achieved at under 35,000 PSI, while keeping flash to a manageable level and with Smith 2.5s and Tauras and Smith 7 shooters, your cases will eject without a Ball-Pein hammer needed!

Think about this. If, .38 Super will chamber in the cylinder of a .357 Magnum, it can be safely fired. The .38 Super has an identical pressure spec of the original 9 X 19 at 35,700 CUP which is close to the Saami +P 9mm spec of 38,500 PSI. So insanity was not one of the features of my .357 Short Magnum. There is no Patent, just CAUTION advised, but stay in the 7-8 powder range and a chronograph is ABSOLUTELY necessary. When you get to .357 Magnum factory velocity, DON'T go any further. There is much less unused case capacity when using one of the mentioned powders. I plan to rework this load with Ramshot True Blue, because I believe it has ideal characteristics. The one I started with originally? Hercules, now Alliant Blue Dot. Muzzle Flash is at least one intense foot of flame! 3N37 will make you believe it is powder formulated by Alchemists!
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Old June 5, 2005, 07:11 AM   #9
WESHOOT2
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Did you know irregardless and regardless mean the same thing? Well, didya?

I test defense ammo outdoors in the dark.

I have observers assist, because flash can be (is) subjective. :barf:

I have noticed that certain guns have different flash signatures than others using same-lot ammo.

Some ammo (powder) flashes about the same through all tested guns, but not always.........
There are some powders one KNOWS will offer excessive flash no matter what gun they get fired from.

I have learned to never assume which powder a factory uses, even proprietaries, because they are free to choose.

I also consider trying to correlate PSI to CUP unscientificalist.

How's that sound?



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"all my ammo is semi-retarded factory ammo"
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Old June 5, 2005, 04:37 PM   #10
Sturm
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We2, I do too. That is if you don't posess the skills. Mathematically, there is no correlation and the pressure is taken at two different locations with two different mesurement systems, but graphically, the two systems can be very closely approximated. I'm not recommending that someone do this for the development of load data, but it is possible to find out how they compare.

I'm glad you have people to assist. Extruded Flake does have it's uses, just not in full pressure defense loads. Blue Dot has provided some of the most accurate loads that I have fired in 9mm, .357 Magnum and .357 Short Magnum and if you fire them in low light you will get a fireball in excess of 1' and PP is just as bright or brighter. Hunting animals or targets, or tin cans and the fireball is not a detriment. Shoot 'em at night and there are several! (i.e. painting yourself as target and the loss of night vision accuaty) Then again, I also recall you mentioning using H-110 in defense loads that were sold to customers, I guess you shot them at night as well.

Sam, I forgot to mention that one of the main area's of difference between the Model 19 and the Model 15 in .38 Sp. is the higher degree of heat treating that is applied to temper the steel of the M-19 over it's .38 counterparts. When Smith went to stainless in the M-66, a lot of the problems were resolved and made the guns so popular early on that a lot of shooters couldn't get their hands on the 66 until production was significantly increased.
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Old June 5, 2005, 07:04 PM   #11
WESHOOT2
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not just me

Local large PD trainer is friend, so I have a fair idea how certain loads (in 9x19, 357 Magnum, 40 S&W, and 45 ACP -- department has since switched to all 40 S&W Glocks) perform at night through multiple guns in front of objective eyes.

More than fair........just not as ready to proclaim absolutes as maybe some others, because I got lots to learn, and I been wrong before. Kinda in the dark, ay?
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Old June 6, 2005, 03:13 AM   #12
Sturm
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Well I once knew a guy who worked on a japanese transmiseon. The only thing I consider absolute is the absurdity that comes from people that have a need to be viewed as experts on the internet when they may in fact be collecting most of what they recommend from other sources.

Either you know this stuff or you don't, and never imagine that there's not someone you can learn from. Works for me, as long as the source appears credible.
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