Is there any subsonic 50 caliber ammunition?

Question

Is there any subsonic 50 caliber ammunition?

Answer 1

There is a plastic training round that is subsonic.

Cartridge, Caliber .50, Ball, Plastic Practice, M858

TM 43-0001-27: M858 Plastic Practice

Used by M2 machine gun with the M3 Recoil Amplifier. The cartridge is intended for scaled range training purposes, where range restrictions limit or prohibit the use of one of the other types of live ammunition.

Maximum range: 765 yards (700 m)

The cartridge is identified by the blue bullet and case which are molded into one piece with high density polyethylene plastic.

Answer 2

Well, my .50 cal Kentucky rifle reproduction fits the ticket. Why would you want to ruin the flattest trajectory of all?

Answer 3

for what purpose would such a thing serve? the only one i can think of would be a misfire.......the 50 cal has a purpose as a 50 cal.....to tell everyone who is the boss.