They have many common interchangeable parts and can be converted from one to the other .
The MSBS - 5.56 K and MSBS - 5.56 B have a cyclic rate of fire of around 700 -- 900 rounds per minute ( RPM ) .
MSBS have many common interchangeable parts and can be converted from one to the other .
The MSBS - 5.56 K and MSBS - 5.56 B have a cyclic rate of fire of around 700 -- 900 rounds per minute ( RPM ) .