正正就係呢個原因...........試想交戰中换匣..........一乸隻直匣要睇下邊度係彈頭邊度係彈尾.......咁就好危險......如果唔睇拍上去...........有2份1機會前後方向掉轉左..........有D真你可以直上.......如M11.......ump.......幽靈m4.......UZI.......等刀可以........插左入去頂唔盡又lock唔穩又要拔番出泥反轉再插............死未...........所以好多機槍刀會考慮呢個因數.......如新款既MP7.......你灣灣地.......M16A1之後亦會用30飛灣匣
PS:以上只係小弟個人睇法,可能好多舊魚.......但這是值得思考既問題.....有錯可插.....但米咁大力