Theirs a lot of screw ups all through history. Gen Custer at the Little Big Horn His men were armed with single shot carbines and pistrols. The Indians were armed with a mix of Repeating Lever action Rifles and Bows and arrows. Custer Loss ( U.S. History) In the Civil War the South lost a big battle because of their Issued ammo. Most were useing birdshot in smooth bore muskets ( limited Range) while the North at that battle used Mini balls, and Buck and Ball as standard issue ammo ( longer range) with a few rifles that were Rifled. (accuarcy).
Veitnam and the M-16, It was issued without a chrome Bore ( no need to keep it clean) and the rifle powder was a dirty Ball type. Thus the weapon jammed often. The U.S. Airforce about this time and a little before figured theirs no need for a gun on aircraft because their would no dog fights. Just hang Air to Air Rockets on them. ( didnt work back to dog fight basics.) and so history goes Just my 2 cents guys Cheers