Shooting a foot high with 125 grainers and you load 158s in it, it'll be shooting even higher, usually. Go lighter to bring the groups down. Last resort, you can adjust your sight picture. 5" at 15, probably too high for just holding the target for a "fine bead" AKA target sight picture vs combat sight picture. Target sight pic is where you put the blade BELOW the bull. Combat is where you cut the bull with the front sight blade.
My Ruger Old Army has adjustables. However, those guns are notorious for shooting way high. I have it adjusted to the bottom of its adjustment and it's still high. It's so high, I have to put the top of the front sight blade in the bottom of the notch and hold the top of the rear notch where I wanna shoot, if that makes sense. It's effed up IMHO, but hey, the gun is accurate and dead on that way. Shy of having a taller front sight blade installed, this is what i have to do with that gun.
Of course, your gun is NOT sight adjustable and you have what you have, so you're just going to have to adjust your sight picture if you can't find a load that shoots POA. Nature of the beast.
I have a Taurus 85SSUL which I did not like the shiney stainless front sight on. It shot pretty close to POA, but I wanted a different sight. 80 bucks to a gunsmith out in Florida (don't remember the name/details) and I had a black front sight dovetail installed and it's adjustable for windage. I filed the sight down for proper elevation. Funny thing, that gun is dead on with 158 +P AND light wadcutters. I'm not saying you should go to this extreme, but I hit dead on and can shoot even out to 100 yards pretty well with that gun, good enough to ring a 14" gong 3 out of 5 if I eat my cherrios, at that range. I hold the front sight high when doing that, hold over at 100 yards being required. It's not practical for self defense practice, but I just like plinkin' with the little fart and my reloads aren't much more expensive than .22LR since I cast my own of free lead. And, hell, ya never know for sure if you'll wind up having to engage a target at extreme range. If it ever happens, I'm ready. It's 3" at 25 yards accurate off the bench.
There is nothing written that you cannot shoot a snubby at 25 or any other yards. There's no law against it. Ignore those "experts" that say it's a "belly gun" and not accurate enough beyond 3 yards or some other BS. These guns are fun plinkers and the more you shoot 'em, the more used to 'em you get. That's a good thing in a carry gun IMHO. Life is SO boring just shooting paper at 3 and 7 yards. BOOOOORING. I like to hear steel go "clang" when I shoot.
We have falling plates and pepper poppers and hanging gongs and such at our club range, most of the members being plinkers like me.
I do enough serious practice at close range in the mean time. But, that's not the only shooting I do by a stretch.