The barrel was shortened nine inches (229 mm) at the muzzle and the gas port and gas cylinder tube were relocated. The modified BAR weighed and was only long overall. Though it proved superior to the M1918 in accuracy when fired prone in automatic mode and equal in accuracy to the standard M1918 at ranges of 500–600 yards (460–550 m) from a rest, it was less accurate when fired from the shoulder, and had a loud report combined with a fierce muzzle blast. Attaching a Cutts compensator materially reduced the muzzle blast, but this was more than offset by the increase in smoke and dust at the muzzle when fired, obscuring the operator's vision. Nor did it improve control of the weapon when fired in bursts of automatic fire. Though the report recommended building six of these short-barreled jungle BARs for further evaluation, no further work was done on the project. The M1918A1, featuring a lightweight spiked bipod with a leg height adjustment feature attached to the gas cylinder and a hinged steel butt plate, was formally approved on 24 June 1937. The M1918A1 was intended to increase the weapon's effectiveness and controllability firing in bursts. Relatively few M1918s were rebuilt to the new M1918A1 standard. In April 1938 work commenced on an improved BAR for the US Army. The army specified a need for a BAR designed to serve in the role of a light machine gun for squad-level support fire. Early prototypes were fitted with barrel-mounted bipods as well as pistol grip housings and a unique rate-of-fire reducer mechanism purchased from FN Herstal. The rate reducer mechanism performed well in trials, and the pistol grip housing enabled the operator to fire more comfortably from the prone position. However, in 1939 the army declared that all modifications to the basic BAR be capable of being retrofitted to earlier M1918 guns with no loss of parts interchangeability. This effectively killed the FN-designed pistol grip and its proven rate reducer mechanism for the new M1918 replacement. Final development of the M1918A2 was authorized on 30 June 1938. The FN-designed pistol grip and rate-reducer mechanism with two rates of automatic fire was shelved in favor of a rate-reducer mechanism designed by Springfield Armory, and housed in the butt stock. The Springfield Armory rate reducer also provided two selectable rates of fully automatic fire only, activated by engaging the selector toggle. Additionally, a skid-footed bipod was fitted to the muzzle end of the barrel, magazine guides were added to the front of the trigger guard, the hand guard was shortened, a heat shield was added to help the cooling process, a small separate stock rest (monopod) was included for attachment to the butt and the weapon's role was changed to that of a squad light machine gun.