With semi-auto pistols, I always load out of the magazine.
I understand that this conversation is about pistols. However, it is equally important to know about how your rifle works. You can load rounds into the chamber of a Remington 700 until the cows come home. You must NOT with a Mauser '98. Some instruction manuals say that you normally load out of the magazine but can, on occasion, drop one in the chamber and allow the extractor to jump over the rim. If you have a Winchester Model 70, it depends on when it was made …