Hot loads in S&W #28 Highway Patrolman?

[Master Blaster]

The flame cutting is self limiting and will not get any worse after a couple thousand rounds.

 

[harmonic]

Re flame cutting, the problem was evident in K frame 357s because of the smaller amount of metal at the top strap. The K frame wasn't intended to digest a regular load of mag ammo, hence the introduction of the L frame.

The 125 grain bullets driven to maximum velocities used large charges of relatively slow-burning powders. Handloaders know the powder types as WW296 and H-110, among others. The combination of slow ball-type powders and the short bearing surface of the 125 bullets allows prolonged gas cutting of the forcing cone and top strap area, accelerating erosion and wear.

Borescope studies of rifle, machine gun, and auto cannon chamber throats shows a lizzard-skin-like texture due to this gas cutting damage, called "brinelling". The results of brinelling are fine microcracks that weaken the surface of the steel, and further promote erosion. In machine guns and auto cannons, barrel life is measured in terms of "useable accuracy", and round counts that determine this are based on group sizes at engagement ranges.

In the K-frame magnums, the forcing cone dimensions combined with the barrel shank dimensions results in a relatively thin shank at the 6 o'clock position, where a machine cut is made to clear the crane. This is usually where the forcing cone cracks. The L and N frames use much beefier barrel shanks and do not have this cut. S&W intended the K frame magnums to be "carried much and fired seldom" service arms, designed to fire .38 Specials indefinitely, with light to moderate use of .357 Magnums. You notice that S&W has discontinued production of K frame .357 magnums, no doubt due to product liability issues and a couple generations of K frame magnum experience.

Back to the OP's question, the problem with the N frame 357 won't be with flame cutting since the frame is much beefier at the top strap.

The problem with the N frame was the cylinder stop. Since the cylinder is so massive, when people fired a lot of double action work, the little piece of metal known as the "cylinder stop," as well as the cylinder stop notch, would sometimes be battered to failure.

Of course, all the above is subject to my ability to remember things correctly, since I've slept since then.

 

[BCRider]

I think your memory is just fine harmonic.

My own M28 not only is showing some slopiness of the cylinder stop within the body opening but there's some peening of the stop notches in the cylinder. I think it saw a lot of fast pull double action work in its past. A slightly slower trigger pull that didn't "flick" the cylinder around so fast would not have produced that peening.

It remains to be seen what, if anything, I'll need to do to fix this or if it needs fixing.

 

[20nickels]

BC,
A new cylinder stop will fix a mild lockup problem, but a serious one where the notches are wallered out needs some gunsmithing. Those notches can be peened back over. This is not a gun for quick double taps.

 

[Owen Sparks]

This suits me as most of my magnum shooting is done single action. I have modern autos for IDPA. I am just looking to get the original punch out of my revolver when I shoot full house loads. Most of my general plinking is with lead bullers at around 1,000 fps.