[LarryNBoise]

Maybe take a look at the photos here and you will have a gauge of what serious forcing cone erosion looks like before it takes leave.

This is one posted here on the forum a short while ago and I would say it classifies as bad forcing cone erosion.

https://www.rugerforum.net/threads/forcing-cone-erosion-how-bad.256745/#lg=thread-256745&slide=0

forcing cone erosion - Google Search

 

[LarryNBoise]

It is my understanding that prolonged use of slow burning powders like H110 for full house loads is the underlying cause of cone and top strap erosion.
This seems to be the natural side effect of this use.
Everything wears out with use, some wear out faster with heavier use.

My favorite 357 loads are with H110 and 110-125 gr boolits. Makes them fly sooooo fast...

In my never-humble opinion, it looks more like rough machining of the forcing cone, but maybe...possibly...perhaps...some erosion where it looks smooth. I polished the forcing cone of my GP 100, and it removed some of the similar-appearing marks. So far, so good, but if in the distant future, it might "need" something, I'll probably try the 11 degree forcing cone reamer. I am no gunsmith, and if I'm wrong, IOWEGAN is welcome to straighten me out! 😊

If IOWEGAN has to straighten you out, you might want to hide that forcing cone reamer!!

 

[LarryNBoise]

That was my old post here. The replacement barrel is showing wear progressing again but because I rarely shoot any 357s now, I'm not worried about it but keep an eye on it. I've got another GP100 that's shot 1000s 357 & 38+P and has no visible wear showing in the forcing cone area.

Good info that Ruger should have to answer for IMO. If the replacement is not on par with the other, something is different in the specs and design or the metallurgy.