Shoot it till it breaks
It's a basic service revolver, not meant for extensive firing of hot .357 loads. If you wanted to shoot a lot of .357 ammo at the range, you should have bought a sturdier gun, like a Ruger GP-100 or a S&W M-686 or one of the big N-frame S&W's.
NO-----First you are spot on with the grips- excellent and coveted.
The 65 was meant to be fired-slick handling, feels good in the hand, the gp-100 is like suggesting driving a duece + half instead of the new Vette he just bought. Speed, service, security Sixes were/are great guns, great trigger, they fit human anatomy better than the gp-100. As for the 686 or N frame they are bigger,heavier, and do not point as well.
"Extensive firing" is truly a garbage term, 1000, 10,000, 40,000 are numbers and mean something. The OP had not said he was buying it to compete, and Plans to beat JM, shooting 125,000+? per year, besides they would be light 38 specials. If he enjoys shooting 125 JHP Mags exclusively and dislikes med 357's, 38+p+ , and the like then he should shoot it till it breaks. If a forcing cone cracks so be it, but if his pleasure comes from 125 gr BTTW loads that is what he should shoot, there is a built in round counter,that lets you know when to stop! Many years ago I took possession of a speed six, 2 3/4" and went to the range, 7 speed loaders filled, and proceeded to empty them and the other 6 rds in the gun, and the 2 in my pocket in less than an hr. I enjoyed it, smart? not really, good practice? No, the last 2 cylinders were truly painful. I still have it today and it still shoots well at 100 yds ( head ) or 3 feet. He got a great gun, he should use it However he most enjoys it. I have seen tests of various 19- models but all were small groups 15-20 guns. Some saw 158 lswc, and cracked, others 125 gr no cracks, while others had cracks with less than 500 125gr in one of the tests. So most all this info is anecdotal at best, is it the 125 gr jump, superheated gasses, metallurgy, luck of the draw. Shoot what you enjoy. Be Safe,