Revolvers take me about 60 rounds to start feeling even remotely comfortable: checking POI/POA, ignition and overall feel/controllability for both hands.
Autos is another issue entirely; I like to have *at least* 6 mags in rotation for working autos, and I need to check those mags in all aspects of function, including a dirty gun. This can get expensive. I usually just take a decent handgun class with the gun/ammo/mags in question--by the end of the course, I have a pretty good idea if it all works together under most likely marginal scenarios (occasionally this makes for a rough class: I had a Bersa thunder .380 that totally crapped the bed under class pressure--that gun and brand is long gone from my own rotation)
This is probably why I have only a couple of autos in rotation (3953, Commander, seecamp) and a pretty strong commitment to GDHP and Fiocch jhp: that's what I was able to get in sufficient quantities to run 8 or 16-hour courses with those guns of late.
The upside is that I am very confident that, say, my 3953 will run dirtied up with any of its 8 mags and Speer 124-gr GDGP in either pressure loading. No guesswork or wishful thinking needed.
Every DA .38/.357 revolver I own is GTG with any maker's version of the FBI load, including buffalo bore (that was expensive, but spread out over time). .357s will both run silvertip 145 all day long as well.