125 grain .357 bullet damage..??

[Varminterror]

As others have stated - keep your foot off of the gas pedal with the 125grn and lighter pills, and you'll avoid trouble. As Drail mentioned, even the venerable 357mag Redhawk with its barrel tenon thicker than the Berlin Wall will be damaged over time if fed a steady diet of light bullets moving at lightning speeds. It's not just a K frame and Six Series issue - those are just more susceptible to more drastic and more rapid damage.

The only thing I seen is light weight bullet recommendation for light framed S&W .357/.38 revolvers. Reason being force of recoil will actually make heavier bullets back out of cases and bind the cylinder. Personally I would not shoot .357 loads out of 12oz or 14oz revolver.

Doesn't happen if the rounds have proper neck tension and crimp, even with 180's. I've never cared to mess with 200-220grn bullets in the airweights, but I've never had any problem keeping the 158's or 180's in place.

 

[tipoc]

Here is a picture of what a light weight high velocity 357 magnum round will do over time. This revolver has seen a heavy round count. And the revolver is a S&W 686. The bottom line is using the full power 125 gr or lighter is harder on a revolver than using the heavier 158 gr rounds
Howard

This is a situation where you have to take care. Care because there is nothing wrong with the gun in the pic. It's a L frame 686 and it will take alot of punishment and honest use. It's just been shot alot over the years, with high velocity light weight bullets (most likely and that's the story) and shows signs of that. That amount of flame cutting poses no risk to the gun and erosion of the forcing cone also poses no threat to further shooting. The greatest risk here is that the lands of the barrel will wear out towards the muzzle and accuracy may suffer.

The discussion around light weight bullets and the .357 Magnum and gun damage revolves entirely around the K frame 357s. The issue was not erosion or flame cutting, but cracked forcing cones. The issue began in the 1970's when a small company called Super Vel run by lee Jurras, began loading 110 and 125 gr. bullets for the 357 Magnum that came close to producing 1400 fps from a 4" barrel. It was also the first jhp that seemed to work well. So the round and the load took off, especially once it developed a great reputation in law enforcement. Other companies followed suit with hot light weight loads.

The M19 and 13 were aimed at law enforcement where it was expected that officers would practice with 38 Spl. and carry .357 on duty. The issue was two fold, 1. that the area of the frame where the barrel was threaded in was quite thin. Under heat it would expand and contract. The other issue was improper maintenance. The build up of lead and copper in the area of the forcing cone needed to be properly cleaned. If not the hotter loads caused increased wear of the area around the forcing cone.

It's been shown many times over the years that with proper maintenance a whole lot of hot 125 gr. loads can be fired through the K frame 357 without major problems. Just keep the guns clean and practice with less hot loads.

tipoc

 

[Varminterror]

The discussion around light weight bullets and the .357 Magnum and gun damage revolves entirely around the K frame 357s.

Also the .357 Max's - where a very real problem for K-frames and Max's and a molehill of an issue with any other 357mag revolver grew into a mountain.

As with most things - it really depends upon your expectation for precision. If you're happy hitting 4" targets at 25yrds, your barrel and bore can take a ton of damage and still deliver. If you're expecting 4" at 150yrds, the tolerance for cone damage is much tighter.

 

[tipoc]

Maybe I'm misunderstanding you but the .357 Max (aka .357 Maximum, or .357 Remington Maximum) is about .300" longer than the .357 Mag and won't fit in a K frame, or even an N frame.

tipoc

 

[Varminterror]

Maybe I'm misunderstanding you but the .357 Max (aka .357 Maximum, or .357 Remington Maximum) is about .300" longer than the .357 Mag and won't fit in a K frame, or even an N frame.

Simply put - yes, you are misunderstanding me.

In no way did I imply the Max fits in a K or N frame.

A very real light bullet problem for Max revolvers, coupled with a very real light bullet problem for K frame revolvers have been misconstrued over the years to magnify a very small non-issue, normal wear and tear in all .357mag revolvers.

 

[Steve C]

The issue with 125gr full power .357 mag loads and forcing cone damage pertains to K frame model 19, 66, 64, etc. The forcing cone cracks on the barrel of these guns due to the machined thinning of the barrel to fit the longer .357 cylinder in the frame sized for .38 spl. (see picture below). The major concern, if you happen to own one of these pistols is that S&W no longer makes replacement barrels for these older models any more so if you crack the forcing cone you probably scrapped the gun unless you are lucky enough to find a replacement barrel that gets more rare every day.

If you look at the new model 66 currently made by Smith you will see that they have redesigned the pistol so it has a full thickness of the forcing cone circumference making it more robust and resistant to cracking. That doesn't mean that you can't crack it with enough hot loads but abuse will damage of destroy any mechanical device though you should have the same durability as a L or N frame capable of firing several thousand rounds of full power factory loads without issue. With a new current production gun you can at least purchase a new barrel should you go crazy enough with full power (1,450 fps) 125gr ammo to damage the forcing cone.

A good article on the issue is found at this link: http://www.gunblast.com/Butch_MagnumLoads.htm

Current production S&W 66.

Older 1970's production S&W 66

 

[Driftwood Johnson]

The forcing cone cracks on the barrel of these guns due to the machined thinning of the barrel to fit the longer .357 cylinder in the frame sized for .38 spl.

Howdy Again

With all due respect, the machined thinning of the forcing cone on K frame revolvers has nothing to do with the length of a 357 Magnum cylinder. As I said in an earlier post, S&W has been putting a relief cut on the underside of the forcing cone of K frame revolvers since dinosaurs roamed the earth, long before the existence of the 357 Magnum cartridge. It has to do with the diameter of the gas ring, that portion of the cylinder that protrudes beyond the front face of the cylinder. The diameter of the gas ring required that in order for the cylinder to close, a clearance cut had to be made on the underside of the forcing cone. Otherwise the cylinder would not close. The amount of material removed in the clearance cut has varied over the years, but every K frame Smith I own, except one, has a clearance cut on the underside of the forcing cone.

Here are some representative photos of a few in my collection of K frames.


38 M&P made in 1920. The relief cut is difficult to see with the less than ideal lighting of this photo, but it is there.

38 M&P made in 1939. Clearly visible relief cut.

K-38 made in 1957

Clearance cut on a 357 Magnum Model 13-2 made in 1979. Clearly, there has been more material removed from the underside of the forcing cone on this revolver than any of the others and the lower portion or the forcing cone is visibly thinner. That is because the gas ring is larger in diameter than any or the others, .435 in diameter. Most of the other gas rings are running around .421 - .423 in diameter. So clearly, with that much material removed from the forcing cone, combined with the power of the 357 Magnum cartridge, cracked forcing cones could become an issue.

Here is the exception to the rule, a 38 M&P Model 1899, made in 1899. Why no relief cut? The gas ring on this revolver is pretty big, .437 in diameter. The answer is the shank of the barrel is thinner, so there was no need for a clearance cut. That football shaped relief on the underside of the top strap is not flame cutting. That is the old Black Powder relief cut that S&W and other revolver makers used to put on the underside of the top strap. Don't forget, the 38 Special cartridge started out as a Black Powder cartridge. The relief cut was put there in the belief that it would provide a place for Black Powder fouling to accumulate without building up sufficiently to bind the cylinder. Eventually the BP relief cut was reduced and finally eliminated.

All this goes to show how the Smith and Wesson hand Ejector design evolved over time. The K frame M&P did not spring fully developed from the minds of the designers at S&W in 1899. Like most manufactured products, it was tweaked and modified over time. With the K frame 357 Magnum revolvers the splitting forcing cone problem became a new issue not seen with the older 38 Special K frames. The ultimate solution was the development of the L frame, a little bit taller, with a little bit more room for the gas ring without needing a clearance cut under the forcing cone.

 

[tipoc]

Driftwood's post shows the issue clearly. Also note that, before the barrels were press fit, the frame and barrel were threaded. This was a thin bit of steel in this area.

It was noted earlier that when Bill Jordan proposed the K frame Combat Magnum to S&W he and S&W saw it as a gun that shot 38 Spl. as it's steady diet with a minimum of .357 Mag through the guns. The K frames are very good at that.

With the rise of combat oriented shooting sports in the 1970's and till now the amount of .357 Magnum rounds that were sold and shot, particularly hotter jhp loads, increased markedly. The issue didn't arise till that occurred.

tipoc

 

[Varminterror]

Interesting to see the carbon blast totally miss the bp recess on that old M&P.

 

[Driftwood Johnson]

Interesting to see the carbon blast totally miss the bp recess on that old M&P.

Yup, it was a pretty useless feature. Here is the BP relief cut in the top strap of a Bisley Colt from 1909. The shape of the cut in a SAA sometimes leads to it being called the Thumbnail. You can see there is a little bit of flame cutting just in front of the relief. I dunno if Colt is still putting this feature in the current 3rd Gen SAA revolvers, but it is in the two 2nd Gens that I shoot regularly in CAS. I only shoot Black Powder in those revolvers, the relief cut never gets filled up with anywhere near enough fouling to bind anything up.

Here is the relief cut in a Colt Army Special, basically the same gun as the Official Police, made in 1921. Well into the Smokeless era. I just looked at a 22 Officer's Model 22 Target revolver, and a similar cut is there too. It has a little bit of a waxy deposit from the 22 bullets, certainly no build up of fouling of any type.

Just checked some Police Positives and Police Positive Specials from the 1920s and 1930s. The relief cut is on them too.