It was based on the French Brandt mortar.

The M1 mortar was used from before World War II until the 1950s when it was replaced by the lighter and longer ranged M29 mortar.

Weight: The M1 mortar's shells sometimes used the same fuzes as the shells for the M2 60 mm mortar.

An adapter collar was added to the smaller fuzes to allow them to fit the larger shells.

It may be found in nearly all the non-Communist countries,[8] including: