Drail,
I don't recall saying anywhere that a Ruger can't be worn out.
Any gun can be worn out, it just takes more to reach that point with a Ruger GP.
125s will tear up any .357, sooner or later. In most cases, sooner.
When I give my opinion of the Ruger being more durable, that's across the board and waaaayyyyy down the road.
This has nothing to do with comparing weights, grip options, sight options, trigger pulls, subjective balance feels, and so on.
The cylinder is stronger, which helps guard against overloads.
The bearing & engagement of the cylinder, "crane", front lockup, and so on are designed to handle repeated pounding of hot loads better than the 686.
The squared topstrap on adjustable sight models is slightly beefier, resisting frame stretch slightly better.
The barrel/frame join is stronger than the Smith 686.
The hand & ratchet teeth will typically wear better and longer, which is one of the reasons Rugers go out of time far less often than Smiths.
And so on.
Again- NEITHER WILL WEAR OUT QUICKLY, AND IT'D TAKE A LOT OF SHOOTING TO REACH THE POINT WHERE THE SUPERIOR STRENGTH & DURABILITY OF THE RUGER WOULD BECOME AN ISSUE.
The Smith is not an "inferior" gun in the general sense of the word.
I have a 586 heavily customized that I'd not hesitate to bet my life on.
It was very much worth spending the money for.
They're great guns, just not built from the ground up for the .357 Mag pressures & recoil impulses.
The GP was.
If sheer longevity is the deciding factor, I'd vote for the Ruger.
If it isn't & you don't plan to shoot 200 full-bore .357 rounds a week year in & year out, then go with the Smith if you LIKE the 686 features.
Most people won't shoot either model enough to notice the difference in longevity between the two.
Everybody has their own selection criteria.
While I prefer the Smith for certain reasons, most of which are largely emotional & "feel", when I take a .357 out in the dirt loaded with 180s for everything from coyote through wolves to small bear, it's strictly a no-emotion sheerly-pragmatic GP.
I have carried both brands on duty. I would not feel undergunned or vulnerable with either gun for duty or personal carry applications.
I bought a 586 the first year it was introduced.
I currently own more Smiths than Rugers.
I'm not a strict brand loyalist, and I use & choose models from both companies for individual applications, where a Ruger might be my "best" choice here, and a Smith might be my "best" choice there.
Stay away from the 125s, or at least keep their use down to a minimum, in either gun.
Denis