They'd lightweight barrels and also the ammunition fed only through the left side. Service trials lifted uncertainties about whether or not the guns would be ideal for aircraft or for anti-plane use. A heavy barrel M1921 was regarded for ground automobiles.[22] The GAU-18/A is a lightweight variant with the M2/M3 https://bookmarkgenius.com/story16822586/the-greatest-guide-to-browning-rifles