So if you stick to 180 - 200 grain hot loads you should be ok?
They'll be better but given enough rounds they'll eventually erode the forcing cone.
It's erosion, it takes place a little at a time and it's accumulative. K frame Smiths don't have as much material and are affected by much less erosion, A GP100 is much thicker around the forcing cone and takes a lot more rounds, but it'll still happen. I heard one report of a GP cracking he claimed something like 20,000 rounds of 125gr bullets with a max load of 296.
Nothing man made is indestructable.