How hot can it handle? 10-6

The numbers are legit, but there are two things to be aware of (this has been discussed here before). 1) The especially fast 38 Specials were intended for revolvers intended for "hi-speed" ammo, like the large framed S&W 38-44 (N frame) and Colt Shooting Master. 2) The velocities for 38 special are from 6" barrels, where today they are from 4" barrels. The 357 magnum velocities were from 8 3/8" barrels, where today they are from 4" barrels.

 

S&W 10-6 pressure? When shell extraction becomes sticky the load is stressing the chambers. That's when you know you have exceeded the chamber pressure limit.
I choose to stay below that threshold, I like my M-10 and hope to shoot it for many years
I only reload brass cases so I have no experience with other metals

 

Stress is put on the chamber with every shot fired, even light loads. If the chamber wasn't there, the brass would blow like a mushroom. It's the chamber that prevents that. It means the expanding brass is putting pressure on the chamber.

If you've exceeded the chamber pressure limit, by definition, the chamber breaks/blows up.

 

Brass is more ductile than steel and has less memory. Steel will expand and return to its original dimension more so than brass. Thus the stuck cases.

 

I seem to recall reading somewhere that S&W not only heat treated the cylinders differently for .357 loads they also strengthened the frame and yoke more on the .357 K frames. I cannot find where I read that though

 

Since it has the model 10 designation, plus p should be fine. If it's commercially loaded ammo you're under what it can do (generally speaking).

 

this seems an interesting video for this discussion
https://www.forgottenweapons.com/elmer-keiths-ka-boom-video/

 

I believe in the anal sphincter reflex when testing loads.

If you are puckered up as you pull the trigger, you should back off the powder charge.

 

On the contrary, the M10-6 in .357 Magnum became the M13-1, which became the M65-1 when they started making them in stainless steel.

Probably in the Standard Catalog of Smith and Wesson. 4th edition, page 217. Right column about halfway down. "The Model 19 is built on a frame that is slightly larger than a standard K frame in the yoke area". I would think that applies to the M10's converted to .357 Magnum as well, and the M13, M66 and M65. K frame .357 Magnum cylinders are longer than those for .38Spl. by 0.05 inches. I can't find any info regarding heat-strengthening of magnum cylinders, but It would be crazy to think they didn't, for a cartridge that develops twice as much pressure as a .38 Spl+P

 

Speer loading manuals have a chart of same .357 ammo fired in a number of different revolvers.
Variation by make, model, barrel length, and variations within tolerance limits give wildly different readings.

 

Can a M10 handle above +P pressure?

Negative, Ghost Rider, the pattern is full.

 

Long as you keep it wet and sticky from lube, it will run solid. Stuck cases are from not enough lube in your gun.

 

I shot one, .38 Special +P in a 10-5 because several "knowledgeable" people said it could handle +P and ended up getting a different cylinder for the gun. The case froze and had to be pounded out with a brass rod and mallet. Afterwards, I found nickel cases would work in the original cylinder but not brass using standard .38 Spec. loads. Later, I was careful to find a used same vintage cylinder that had the same type of paws and timing was not affected. After a few years, I found a nice 586 nickel and use that when I want to shoot hotter loads.

 

That is really surprising to me. Was it an off the shelf load?

My j frames and k frames live off remington 125 gr jhp plus p. It used to be like 5/50 at walmart...cheaper than lrn reloads.

Never noticed any issue, nice little extra oomph.

 

Talking practical numbers, you could expect even an earlier M&P (let’s assume a 4” or longer barrel) to eat [email protected] loads without exploding or wearing out within a few tens of thousands of rounds. Go up from there in velocity and I would expect issues within a few thousand rounds if not a cracked forcing cone or worse. That said, shoot 100k rounds of [email protected] loads and you would probably end up with a pretty clapped out gun at that point.

 

No these were handloads. I was using CFE Pistol working up a load to 4.9 grains under a 158 grain XTP seated at 1.455. All within Hodgden's specs. I was just starting to work up a +P load starting at 5.1 grains. Hodgden states that 5.0 grains yields 914fps and 5.4 yields 986fps. As for the gun, it only had 200 "off the shelf" rounds through it when I got it.

 

They probably will handle 38-44 cartridge data but I see no reason to.

 

A few decades ago, when I was much younger, and in the process of acquiring wisdom, I loaded some hot .38 Specials. I still have most of the box of a couple of them. The hottest was probably 9.8 gr of HS-6 with a Winchester 110 gr JHP and a CCI-550 primer. (Current +P max of 8.4 gr, according to Hodgdon data), while the other was 9.4 gr of Accurate No. 5 with the same bullet and CCI-500 primers (current +P max shows 7.9 gr both with the 110 gr Hornady XTP). DO NOT USE THESE LOADS TODAY. I fired them in a .38 Special, but it was sort of a “special” special: a Ruger Speed Six, which was literally the same revolver as their .357 Magnum Speed Six with the cylinders bored shorter for the .38 Special cartridge.
While both of these loads exceed +P pressure, they are both under the starting load currently listed for .357 Magnum with the Hornady 110 gr XTP, and my Speed Six seemed to handle them just fine. Likewise, with my SP-101 chambered for .357 Magnum.
As an aside, my Ruger Security Six and Speed Six .357 Magnums handled thousands of full house .357 Magnum 125 gr JHP handloads without issue, while my handloading hot rod buddy’s Model 19 cracked it’s forcing cone in just a few hundred of the 125 gr JHP loads with W-296. I wouldn’t push a Model 10 past current published +P load data.
As I said, it was a long time ago, (1989, to be exact) and today I stick to tried and true loads that are within published manuals. And I no longer have a revolver chambered in .38 Special, and NEVER would have fired one of those handloads in a S&W Model 10, 14 or 15, much less a Smith J frame or Colt D frame.

 

I’ve heard just the opposite. Lube in the chamber basically turns it into a hydraulic cylinder when the round fires and expands. Causing frame stretching and end shake.

 

In a long ago Guns & Ammo article writer Jan Libourel toured the S&W factory and stated that the 38 and 357 cylinders were machined from the same bar stock and he saw both loaded together in the same heat treat tray and slid in the heat treat oven. (he even provided a picture) So he was saying they are both the same except for different chambering.

That being being said if I wanted hot 38s I would stick to the hottest book loads and no hotter. If you want above 38 special +P power but less than 357 then buy a 357 and load mid range 357 loads in 357 cases so they don't accidentally find there way into a J-Frame 38. My mid range loads are 6.6grs of Unique with a 158gr lead SWC bullet. Those get around 1100+FPS from a 4" barrel. Thats a big step up over all but the hottest 38 loads and should be safe in your gun. And they don't have the ear busting blast of a full power 357 load. They are by far my most shot 357 loads.

My hottest 38s are 158gr lead bullets with 8.4grs of Blue Dot powder. That load came from the Speer #10 manual and was listed as a +P load for 158gr jacketed bullets for around 900fps. The lead bullets will pick up more speed and should be close to 1,000fps. I know they have some stiff recoil in a skinny barrel model 10. But should be perfectly safe in any K-Frame gun. But I wouldn't use them in a J-Frame of any kind.

 

Unless my gunsmith could convince me that other than chamber depth the guns are the same, I'm going to opine that the Model 10 is not the place for tomfoolery.

Absolutely not, some of those loads are well in excess of 40,000psi.

 

Just an FYI, these are what ammo makers in the past said about .38-44 ammo.

Source: https://cartridgecollectors.org/ammunition-catalogs

--------------
1939 Peters. Ballistics were 158 grain bullets at 1115 fps from 5” and 6” barrels.

Page 32.

Items marked (T) are designed especially for the .38-44 Smith & Wesson Revolver and the .38 Colt Shooting Master. Pressure of these two cartridges is safe for lighter guns, but the recoil is likely to be more unpleasant and the frame may be shaken loose in time.

These two cartridges:

.38 Special Hi-Speed.

.38-44 Special

----------------------------------

1933 Remington Arms

.38/44 Smith & Wesson Special. (page 5)

Ballistics: 158 grain bullet 1125 fps in a 6” barrel. (page

Adapted to new .38-44 Smith & Wesson Special Revolver; also safe to use in Smith & Wesson and Colt Revolvers chambered in the .38 Special cartridge if they are in good condition. In these lighter models the recoil is noticeably heavier. May also be used in the Colt “Shooting Master”.

.38 Colt Special Hi-Speed. (page 5)

Ballistics: 158 grain bullet 1125 fps in a 6” barrel.

Adapted to Colt “Shooting Master” Revolver and other Colt’s and Smith & Wesson revolvers chambered in .38 Special Cartridges, if in good condition. Recoil will be heavier, however, in lighter arms.

On the page for interchangeability of cartridges:

Items marked (T) are designed especially for the .38-44 Smith & Wesson Revolver and the .38 Colt Shooting Master. Pressure of these two cartridges are safe for lighter guns, but the recoil is likely to be more unpleasant and the frame may be shaken loose in time.

------------------------------------
Winchester 1943-1945 Ammunition handbook.

Ballistics: 38-44, 150 grain bullet at 1175 fps from a 5” barrel. Page 63.

Page 68. Lists all the .38 Specials including .38-44 under “Cartridges of different names interchangeable and adapted to the same guns”.

Same description in Winchester - Western catalog of 1960. Page 36.

Ballistics of Super-X 150 grain bullet is 1065 fps from a 5” barrel. Page 34.
============

Bottom line: ammo manufacturers at the time thought the pressure of the .38-44 ammo was safe in smaller/lighter framed .38 Special revolvers, the caveat being they were in good condition.

 

Source for pressure measurements? Thanks.

 

And most today would deem that imprudent. Nobody was shooting thousands of them either.

There haven't been any factory loadings in several decades. The person I quoted mentioned "data". That covers a broad range. Keith's .38-44 was tested at well over 40,000psi, as I already said.