When your AR-15 fires its last round, the bolt locks back and the trigger won't fire. That's your signal to reload. Look over the top and you'll see the bolt locked open and the dust cover down.

Standard (emergency) reload:

1. Press the magazine release to drop the empty magazine. At the same time, reach for a fresh one with your support hand.
2. Keep spare magazines oriented rounds facing backward in your pouch or pocket so they come out ready to insert.
3. Insert the new magazine firmly into the mag well.
4. Pull down to make sure it's seated.
5. Press the bolt release to chamber a round. You're back in the fight.

Reload with retention: an empty magazine is worthless, but a partially full one still holds rounds you might need. If you want a fresh magazine without losing those rounds:

1. Bring the fresh magazine up next to the one in the rifle, holding both in an L shape.
2. Press the magazine release and ease out the partial magazine.
3. Rotate the fresh magazine in, seat it firmly, and pull down to confirm.
4. Stow the partial magazine in a pocket or mag pouch so the rounds stay on you.

Can't hold the rifle up one-handed? Tuck the stock under your arm and follow the same steps.