I got a set of pin gages on sale a few years ago. I also eventually got a good electronic, internal mic. I have used them to measure all my revolvers. The only ones that were consistently tight were Ruger .45 Colt NMBH’s. They tended to around 0.450”, but varied significantly among chambers, and among the several guns. My .357’s were 0.3571” on my S&W 627PC, to 0.3590” on 50th Anniversary Ruger Blackhawk. My most accurate .357 may be my 45 yr. old S&W Model 27-2 at 0.3586”. Most of my .44’s tend to be slightly on the big side, except my DW 744, which was ridiculously tight at 0.428”. I got the Manson reamers from Brownell’s for .44 and .45 Colt. The DW is now 0.4318” and is the most accurate .44 I have. My other .44’s run from 0.4324” to 0.4327” and they are also nicely accurate. My reamed .45 NMBH tend to around 0.4528”. They now shoot much better than they did originally. Part of the reason for this is, that in addition to being tight, the throats tended to “colorful” shapes, like oval, or S shaped, or tapered. Fortunately there was enough material that after reaming they were as cylindrical as I could get them and they shot much better.
The bottom line is, measure carefully before you spend money on a reamer. IME, the .357’s tend to be a bit oversized, rather than undersized. And what is also critical in a revolver is chamber alignment with the barrel. I look at the distribution of fouling in the forcing cone to see if the chambers are aligned. If they aren’t, then ministrations of a competent gunsmith are required.