If the AK-47 is supposedly the best firearm, why doesn't the US military use it?

The AK-47 is cheap, very reliable, and simple to train and maintain. It has been said the first child's weapon should be a AK-47, because almost impossible make it not work.

It is very effective in combat, but not the best in every way. Most weapons from the M-16 forward are lighter that. The AK-47 is good at short range, but not longer ranges, as it is not accurate at longer ranges compared to other weapons.

With a M-16, with the same weight, a soldier could carry about twice as many rounds as a soldier with a AK.

One big problem with the entire AK series is it is impossible to make a internal silenced version of them. This is how you do it.

Add a foot or more to the end of it.

Silencers are useful in mainly twice situations, long ranges, or urban close combat, like inside a building. The AK is already bad at long range, and a extra foot isn't what you want on your weapon inside a building during combat.

Source: QUORA