Just like to have some opinions.
I have an older Model S&W Model 19 4" and have been loading Lee 158 gr RNFP cast ACWW and Lyman #358429 both with 6.5 gr of Unique, in .357 magnum cases. Shoots nice small groups.
I have researched and read all the stories of the K-frame magnums and the abuse and damage caused by the 125 gr. jacketed mag loads used by L.E. officers in years gone by......cracked barrels @ the 6 o'clock position, burned out throats, excessive end-shake, etc. The 125 gr being a very short bullet, the high pressure and flame temp of the magnum powder charge and the flat cut machined into the bottom of the barrel at the throat area all working together to beat up the k-frame revolvers.
Does the above listed loads...158-170gr cast and 6.5 gr/Unique in .357 magnum case, sound mild enough for long term use in the S&W Model 19 K-frame?
I have a S&W 586 4 inch that I use for full-magnum hunting loads with 2400 and H110 powder. And most of the time, I shoot the above mentioned lighter loads in the Model 586 also.