Repeatedly cycling a round into the chamber and ejecting that same round will definitely cause bullet set-back in VERY short order. That, of course, creates an EXCEEDINGLY dangerous OVER-PRESSURE condition.
Unless you are interested in having a really exciting time the next time you fire that pistol, please discard any round that has had ANY amount of bullet set-back. The best procedure for folks carrying for defense, whether LE or not, is to NOT load and unload except after a range session, and then rotate which round is the top round, and INSPECT all rounds by standing them up and using a straight edge on top to see if any bullet set-back has occurred. Discard any rounds that do not pass this test.
Chambering a round without feeding through the magazine is also to be avoided. No one really ever did this until the Mel Gibson movie, and Beretta thereafter claimed you can do it with the M9 (the pistol used in the "suicide" scene in Lethal Weapon. Perhaps you can with a Beretta, but I would not wish to test it on a day-in, day-out basis.
Generally, pistol extractors are designed to work like the Mauser 98 rifle. Thus, they are designed to let the cartridge slide up behind the extractor as the pick-up rail strips the top round from the magazine.
Dropping a round into the chamber and then letting the slide drop slowly often will not allow the slide to fully close, and letting the slide slam forward has been known to snap off the extractor hook. Neither result is preferred. I recommend you always chamber a round by running it through the magazine, even if it is a single round.
