Mod 28 gas cutting ??

[SOFMatchstaff]

What would be the limits of gas cutting on the frame of a Mod 28? Has anyone welded on a frame? This was a rental and its is as bad as I have ever seen. I need a new barrel as it is literally shot out, so the barrel has to come out anyhow. Im thinking a stainless Tig to fill the canyon.

 

[stansdds]

Let's see a picture of the eroded area.

 

[shocker]

Literally shot out a barrel? Like 100,000 rounds of factory ammo loaded with H110?
Frame erosion tends reach it's own limit so unless you continue to fire lots of max loads with known to erode propellants I'd leave it rather than weld on a forging.

 

[ddixie884]

I have also heard and read that it is a self limiting condition. Of coarse they could all be wrong......

 

[Abflyboy]

Pics? I am curious what makes the barrel 'shot out'.

I have several 629's that have flame cutting. It got to a certain point then stopped.

 

[chief38]

IMHO the .357 Magnum was originally designed for shooting with a 158 grain slug. It is pretty much known that the lighter the bullet one shoots the more the gun is subjected to flame cutting.

My advise (and what I do) is to only shoot 158 grain Mags for general shooting. While the 125 grain has a better reputation as a stopper, I'd limit those to as few as possible. After a few practice shots you will know where they hit and so the fewer the better. If you wanted to load them for SD/HD and very rarely shoot light billets your flame cutting would be minimalized.

 

[chief38]

As far as tig welding - I do not know how welding would affect the integrity of the revolver. Personally, unless there was no choice in the matter, I'd not do so but I'm certainly not a welder or a metallurgist.

 

[SOFMatchstaff]

I still havent got an answer to the two questions I posed...I would like information, not opinions or history lessons. Experience and measurement values would be appreciated.
thanks

 

[ggibson511960]

I still havent got an answer to the two questions I posed...I would like information, not opinions or history lessons. Experience and measurement values would be appreciated.
thanks

I'll take a stab at answering the first question. There is no way to evaluate a tolerable safe limit of erosion. One could carefully measure the reduction of area in the top strap and calculate a theoretical stress increase, but there is no rational way to evaluate the increased risk of fracture from stress intensification from notches or cracks because the damaged area is irregular. A stress analysis of the top strap section would quickly run up against what acceptance criteria to use, i.e., what are the normal and proof loadings imposed on the part and what is an allowable stress. It is generally accepted, but not known for certain, that S&W frames are forged and heat treated 4140 chrome-molybdenum carbon steel. S&W is not going to tell you what it's made of, nor how it's heat treated. One thing is certain. Welding on the frame will create a heat affected zone with different properties than the base material including yield strength, tensile strength, fracture toughness and corrosion resistance, none of them any better.

If it were my M-28 and the visible gas cutting was more than 0.005 in., or if it was really jagged and pitted, I would dye penetrant test it to get a seat-of-the-pants feel for any gross cracking, pitting or slag inclusion. You could peen down any gnarly material, but the best solution would be a stainless steel guard strip to sacrificially absorb future abuse.

 

[Hair Trigger]

I still havent got an answer to the two questions I posed...I would like information, not opinions or history lessons. Experience and measurement values would be appreciated.
thanks

No way to give an educated evaluation without a picture of the flame cut.

As for welding of any type, my guess is the heat will warp the frame and ruin the gun for sure.

 

[ken158]

First time I ever heard of a 28 having flame cutting that turned into a problem. Also curious who decided the barrel was shot out... Wondering how much lead is in the barrel to make it appear smooth maybe?

 

[Erocksmash]

Could possibly be micro welded, BMCM here on the forum is the connect for that and has helped me before...

If the barrel is shot and flame cut is that sounds like a parts gun IMO

 

[harvester1]

Size wise how does the flame cutting compare to the fouling cups on older guns?

 

[BigBill]

What's the cause for flame cutting?
Hotter loads?
A while back here it was mentioned that 296 powder causes it.
Or is the cylinder to barrel gap too big?

I only use 2400 powder for magnum loads and unique powder for leadcast loads. I don't use 296 powder anymore I get more mileage with the 2400.

The metallurgy can change as little as 400 degrees. Welding might not be good for the heat treat.

 

[LAWMAN662]

What did S&W tell you?