The M11 is a practice version of the M9 antitank grenade. It consists of two parts, a head assembly and a stabilizer assembly. The head is acorn shaped, made of cast iron, it also has a threaded base to receive the stabilizer assembly. The stabilizer is made of sheet steel with the threaded adapter rivetted to the tube. The fins are spot welded to the bottom of the tube
The M9 antitank grenade was adopted Dec. 30 1940. The igniter was placed in the nose which caused many problems. If the safty pin was pulled and then dropped, it was very likley to detonate apon impact with the ground. The grenade would also have to impact a tank or hard surface at a very precise angle for the fuse to work propperly.
The M11a1 is a practice version of the M9a1. It is made of two pieces, the head wich is made of sheet steel and the two pieces of the head are crimped together with no way of changeing the nose if damaged. The tail section has welded fins which also had to be replaced with any damage.
The M11a2 was made of four parts so that if any part was damaged it could be replaced and fired again. The metal ogive and cast iron body are criped together. The tail tube is rivetted to the threaded adapter and the fins are loose of the stabilizer tube.
All practice greandes are painted black with white markings.
The M11a3 is constucted of four pieces. the only difference between the a2 and a3 is the treaded adapter was crimped and then spot welded to the stabilizer tube.
The M11a4 is also constructed of four pieces. The treaded adapter shows no signs of being crimped but casted or welded into the tube. The M11a4 was also kept around for practice long after the M9 grenade was abolished.
The M9a1 antitank grenade is made of sheet steel with a metal wind screen that also provides the proper stand off for the shape charge. The grenade has a base impact inertia fuze. The grenade was initally painted yellow with black markings but by 1943 color codes were changed and the grenade was painted OD with yellow markings. The grenade had a range of 184 yards when fired from the M1 carbine or 287 yards when fired from the M1 rifle.