Material showing a large assault mortar being tested.
Unissued / Unused material.
Battle of Saipan.
M/S's as a giant assault mortar is towed by lorry. M/S's as it is run into position in a pit, loaded and fixed. C/U hands pressing button, it is fired and shell is seen exploding. M/S as a U.S. soldier clambers out of huge crater caused by shell.