Is it "good" out to 15 yards? Oh yeah, it'll shoot that far -- and more. Whether or not it's accurate ... depends. I own a few. One is a 1849 Uberti, with maybe 3" barrel (?) and this is the most accurate, but it's not a tack shooter. In fact I rarly shoot it at THAT distance.
The second is a Uberti...I think it's called the Wells Fargo. It has no loading lever and the bolt holes are oval. To load you disassemble the revolver. It's similar in accuracy to the 1st Uberti.
Then I have an 1849 Colt with 5" barrel that I got a LONG time ago made by Armi San Marco. It is not accurate at all, but it does hit the target.
I have a Remington .31 brass frame that's ASM, and that's not too accurate -- about like the ASM I noted above. I also have a steel frame version of this Rem. made by Pietta. It is, however, a pretty new gun and I haven't been able to shoot it yet.
The instructions about loads are given with the revolver. I usually only load about 12 grains at MOST in mine.
These are fun little guns, even though I believe they're not as accurate as the .36 cal revolvers (those I have found are pretty good with accuracy -- esp. the Uberti & Pietta) They were originally intended to be close quarters guns for personal defense, so expecting them to be really accurate may be expecting too much.
I say, stay with Uberti or Pietta. Palmetto makes some of these but you're taking a big gamble with your $$ on them when those two prior makers have a better reputation.
Go ahead. If you don't expect great accuracy, but just want some informal fun, they're great!