Are the M16A1s and M16A2s semi or full auto?
The M16 rifles have three selector settings. On the M16A1, they
are Safe - Full - Auto, and the A1 series rifles are capable of
unrestricted full auto fire.
On the M16A2, M16A4, and M4, the selector settings are Safe -
Full - Burst, and they are limited to three round bursts.