Short version:

Is there a practical wear and tear difference between a 125gr @ 1200fps 38 +P, and a 125gr @ 1200fps .357 Magnum round?

Longer version:

So I'm looking to grab some additional JHP ammunition, maybe for eventual carry... but maybe I don't need to?

I have a little bit of the "lite" Remington .357 Magnum Golden Saber 125gr @ 1200fps ammunition.
I'm contemplating buying some Underwood .38 +P Gold Dot 125gr @ 1200fps.
The thought being the hot .38 +P ammo would be less wear on my 65-5 & 19-4 revolvers than the "Magnum" ammunition I already have.

My question... are these rounds, as far as wear and tear on the gun is concerned, essentially the same? I'm no reloader, but I am aware of the various SAAMI pressure specs for .38s and .357 are quite different. Getting something that weighs 125gr to go 1200fps would seem like the same pressure, heat, powder burn rate, etc... to me and thus the same wear on the guns.

Again, this is more about the ammo as opposed to "can I shoot it" or "will it break my gun". I'm aware of the "controversies" that sometimes come up with K frames and 357 ammunition. I fire 158gr @ 1200fps 357 ammunition from them with some regularity. That's just getting a bit rough on my wrists though, so I'm looking for something "hot, but not too hot" and in a lighter weight for less felt recoil, that won't ruin the guns if I light off a few hundred rounds a year in each for the next 20 years.

Thanks!

The 125gr magnum load has to leave its case to get to the barrel.
The 38 case with a 125gr bullet has a lot of travel to get to the barrel and could cause a problem if the cylinder is out of time.

One reason the 158gr bullet is well liked since it is at or in the barrel, when fired.

Excellent point Ed. Going down that road, relative to the whole "K frame gas cutting/forcing cone" issue, a 125gr/1200fps Mag might be preferable to a 125gr/120fps 38 in terms of wear on the gun.

Thanks!