When they installed a bomber cannon on an M1 Garand, the Japanese nicknamed them “monster weapons”.

At 10 p.m. on November 17, 1944, Sergeant Mel Grevich stood in a warehouse at Camp Tarowa, Hawaii, staring at a row of damaged aircraft ready for scrap. At 26 years old, after 18 months in the Pacific, no innovation had saved lives. His battalion had lost 11 gunners in the past four weeks during training exercises.
The problem lay in the rate of fire. The M1919 A6 light machine gun weighed 14.5 kg and fired 400 rounds per minute. The German MG42s fired 1,200 rounds per minute. The Japanese Type 92s, 450. The American Marines were vastly outmatched in firepower. Grevich had seen three machine gunners die at Bugenville because they were unable to provide sufficiently rapid suppressive fire.

The enemy was simply advancing by exploiting gaps in their firing positions. Grevich was assigned to G Company of the 28th Marine Regiment, 5th Marine Division. The regiment was preparing for the invasion of Ewima. Intelligence indicated that 21,000 Japanese defenders were entrenched in a 18-kilometer network of underground tunnels. The Marines would be landing on black volcanic sand, without any cover.