That is an excellent question!
Most of the problems regarding the M19 stem from the weakest part of the gun which is the forcing cone area and the top strap just above it. The M19 is a K-Frame and other K-Frame models chambered in .357 would therefore be susceptible to the same set of parameters.
The M19 was a much more popular gun than the M13, and because of that it has had more exposure to failure than the M13 has had. The M13 and it's Stainless twin, the M65 was widely purchased in the 3" barrel length for CCW by Law Enforcement, and was basically a "carry gun", therefore probably not shot nearly as much as the M19's have been, therefore the same problems were not showing up as much.
The other factor that caused problems with the M19 was just around the time that it became so popular with the shooting public, the 125 grain .357 Magnum was enjoying it's #1 spot for being a "Man-stopper". The 125 grain bullets under the Magnum pressures was discovered to be problematic in K-Frame 357's and caused flame cutting, erosion of the forcing cone area, and frame & barrel cracking. The M13's were routinely issued to L/E with 38 Special +P or +P+ ammo and so they were not subjected to the same amount of abuse as the M19's.
All that said; I own both a M19 and a M65 ( stainless twin of the M13) and have shot the heck out of both of them with Magnums. I avoid 125 grain bullets and I have had no problems with either revolver. Most of my friends also own similar guns and they have not experienced any problems either. Since I bought my 6" M19 used, I have no idea what was shot through it prior to being owned by me, but again there are no problems with it.
As a carry gun, the M13 (and its sisters) are GREAT choices. They allow .357 ammo to be used, are nice smooth, concealable and reliable revolvers, and are deadly accurate. I wold just stay away from shooting 125 grain Magnum bullets in them.
Now I have also worked on many M19, M66, M65, M13 revolvers and can honestly say that despite all the hype about their weaknesses I have not personally seen any cracked frames yet. Not saying that they haven't had problems, but I have yet to personally or physically see any. I think by now most owners know to stay away from the lighter bullets and have shot limited amounts of 357 Magnum ammo through them. People who want to pound out large quantities of Magnum ammo shoot it out of L or N frames, and keep the K-Frames more for carry purposes.
Hope this long-winded response was helpful in answering your question.
Chief38
I also recall that S&W blamed ammunition from a specific manufacturer. That manfacturer had some cracked barrels examined and determined it was a metalurgy problem with the barrels. When they brought this to S&W's attention, the story goes that S&W told them to keep it to themselves and removed the faulty barrels - to storage. A few years later, still during 19-5 production, another manager put the ill made barrels back into the production line. Viola !!! "weak" K-frame magnums.
