I had a Ruger "service revolver" with a 4" bbl...that thing was accurate to as far as you could see.....I'm guessing a 3" bbl can be too.

I went to a qualifying competition once, one of the stages was with a snub nosed revolver, which I didn't have, but one of the guys loaned me his.. I think it was a colt with 1 1/2" bbl....

I thought I was good, and I was, lol, but that thing humbled me bad, lol...I used to get a kick out of seeing Telly Savalas on Kojack picking guys off a high roof with his little snub nose...

I regularly shoot my S&W 66-1 4” barrel to 100 yards offhand on a 10” plate. I even hit it now and again. Lol

Seriously, 4” plates are not a big challenge at 25 yards offhand both SA/DA. My 50 yard targets are 8” plates.

The 100 yard target is used as a tie breaker when needed.

I can hit a 12 inch steel target at 100 yards better than half of the time with a Glock and the other misses are not far off the edge of the plate.
add a dot and it is like 9 out of 10 standing

you do not want to be getting shot at from 100 yards with even a G19 and anyone who knows what they are doing or doesn't. really dumb luck happens a lot. I had a cousin that shot 2 of 3 deer with a scope that was 6 inches right at 30 yards both deer were facing left and he always aims at the point of the shoulder , he missed the one facing right and added 2 hits right of where he expected and a clean miss at 60 yards , we found a carboard propped it up against a stump and made a mark to shoot at , yup 6 inches right at 30 yards.

zero or sight in doesn't really speak to effective range of a persons shooting but it can give you a good start at normal ranges

if you run a 124gr 9mm 1100fps from a gun with a 5/8 inch height over bore cutting the right at the top edge of the sight at 7 yards BC .161

you are
on at 7
1/2 inch high at 20yards
on again at 50 yards
3 inches low at 75 yards
8 inches low at 100 yards

that is darn effective for any sort of practical shooting you would likely be doing with a 4 1/2 inch barrel gun

that will be right about where most of your factory sights are set that have no elevation adjustment

Alright here's the dirty secret on my 100yd beer money shot. Gimme 2-3 sighter shots on the bare dusty dirt strip pit that I shot at, hang the pie pan on a 55 gallon drum. Walk it in noting where the dust kicks up. Once you hear the drum memorize the sight picture or better yet count the serrations on the front sight above the rear as you go and mark the one to line up on the rear with a #2 pencil.

BTW, Elmer covered this in his book Sixguns. Some of his front sights had inlaid gold wire just for distance shooting.

BTW, it was a two inch barrel and a skill for young eyes. IIRC, I held about two thirds of the front above the rear to lob it downrange.