Noop. an M16 fires a 5.56mm (or .223 caliber) bullet. A .45 caliber shoots a bullet that is ~11.43mm.
The M4A1 carbine is chambered for the 5.56x45mm NATOcartridge, the same as the assault rifle it was derived from, the M16. It is also capable of firing the .223 Remington sporting cartridge.
Either an M4A1 or M16
The 6.8 mm SPC is a new cartridge being considered by the US military. About the same length as the current 5.56 cartridge used in the M16 rifle, it has a fatter bullet- about .277 caliber.
In the 1960's there was the Gyrojet gun which were actually miniature rockets but the caliber was larger than the .223 round of the M16
The typical AR15 fires the same type of bullet as the M16: a .223 caliber (5.56mmx45mm NATO) round. There are AR-15 rifles that have special barrels made for a variety of popular cartridges, even the little .22LR.
5.56mm by 45mm long. This is similar to, but not the same as .223
.223
5.56 The cartridge used in a M-16 is a 5.56mm caliber Nato round It is also referred to as .223 caliber Remington. The actual bullet is small, weighing between 46 to 52 grains and having a true diameter of .224 inches. Bullet and case are 5.4 cm long
Bullets alone have no velocity. The .223 CARTRIDGE, when fired from an M16 rifle, will drive its bullet at about 3,200 fps. However, velocity depends on the makeup of the cartridge (powder charge, bullet weight) , and which firearm it is fired from.
5.56x45.223 or 5.56
the m16 uses 5.56 caliber ammo