One round in the chamber, and (normally) 20 or 30 rounds in the magazine. However, there are magazines that hold 5, 10, 40, 45, 90, and 100 rounds of ammunition, each with varying degrees of reliability.
It also depends on what round that particular AR-15 is chambered for.
How many bullets can a 9mm baretta hold
It can hold 10 bullets amd it's semi-automatic.
35
Which model?
30
poor llama...
6
11
Six rounds.
9
two
14