I remember the 3 7/8" BHG .45 - it had to have a shorter throw extractor and a flat-headed base pin. I shot two of those at the range - and the extraction was difficult. Also, that flat-headed base pin would release itself under recoil at odd times. A 4 5/8", that's only 3/4" more barrel, has both a full length extractor that dumps the spent rounds easily and completely and a regular base pin that stays put. I had one for years - it was fun, but never would be mistaken for a CCW!
I also had a .32 H&RM and .357M version - and made a .44 Magnum version from a QPR BHG and new SBH. All were 4 5/8" with similar black Micarta BHG panels. Fun revolvers - especially the SBH .44 when you stayed with .44 Russians and Specials. One day I realized I hadn't shot the SA's in quite some time - and sold/traded them all away.
My Ruger SA experience started >10.5 yr ago with a .45 convertible BH - initially shooting my left over .45 ACPs from a G21 I had sold. One day I tried .45 Colt... and never touched the .45 ACP cylinder again. Several .45 Colt SAs - and a .454/.45 SRH and S&W .45 Colt 625MG later - I started reloading .45 Colts (Later adding .45 ACP and a lot more!), making them even more affordable. Today - without my reloading tools - I'd consider the .45 ACP again - but only in a DA revolver - like my 625JM - great value and super fun.
Stainz