LarryF,
Do NOT place any rounds directly into the pistol's chamber! Load the magazine, then rack the slide to let the pistol feed a round into the chamber.
Manually inserting a round into the chamber is a BAD idea. It's possible, but why do it? If you want to have a loaded chamber and fully loaded magazine, follow these steps (and be sure to check step #9 before you begin):
1) Remove the magazine from the pistol.
2) Cycle the slide and inspect the chamber to make sure it's empty.
3) Use the slide stop lever to lock the slide open.
4) Load the magazine to full capacity.
5) Holding the pistol in your dominant hand, point it in a SAFE direction with your finger OUTSIDE of the trigger guard.
6) Use your non-dominant hand to insert the loaded magazine. Be sure to insert it forcefully enough to let it "click" into its fully seated position.
7) While keeping the pistol pointed in a safe direction and your finger away from the trigger, use your non-dominant hand to pull the slide rearwards as far as it will go. Note: Novice shooters often turn the pistol sideways (to their left, if right-handed) while performing this step. Please don't get into the habit of doing that; it really upsets the other shooters when you're at a range!
8) While maintaining a safe muzzle direction and keeping the finger away from the trigger (am I emphasizing that enough?
), release the slide. It will snap forwards under spring pressure and feed a round from the magazine to the chamber. THE PISTOL IS NOW READY TO FIRE! Of course, we all observe Rule #1 and treat all guns as if loaded anyway, right?
9) At this point, depending upon the design of the pistol, you may need to use a safety or decocking lever to put the pistol into its "carry" condition. You should read your owner's manual and practice operating such a lever several times BEFORE reaching this point with a round in the chamber! Do NOT try to lower the hammer by pulling the trigger and/or easing it down with your thumb; this is a good way to shoot yourself in the foot!
10) Press the magazine release and remove the magazine. Have your non-dominant hand in place to catch it BEFORE pressing the release. Also, note that even though the magazine is out, there is still a round in the chamber. THE PISTOL IS STILL LOADED!
11) Carefully set the pistol down (or holster it, if you're wearing one and able to re-holster smoothly and safely) with the muzzle pointing in a safe direction.
12) Load another round into the magazine to bring it back to full capacity.
13) Repeat steps #5 and #6.
If you have two magazines (and you should), you can see that this process can be simplified a bit by starting with one mag fully loaded and the other mag loaded with only the initial round to be fed into the chamber.
A few additional things to consider:
1) Mechanical safeties can fail. Anytime you de-cock the pistol, be doubly sure to have it pointed in a safe direction.
2) If you were to manually insert a round in the chamber, then insert a loaded magazine and let the slide go forward, the round stripped out of the magazine would smack into the round already in the chamber. This could result in a bullet striking a primer, resulting the pistol firing out of battery, resulting in a wrecked pistol and quite possibly wrecked fingers, eyes, et cetera. Don't do it!