shooter=棘手槍(電影)一問???

If you mean the one that he shot down the helicopter with, it is the 50 calibre barrett sniper rifle- fully automatic with ten 50 calibre shots. If you really want to be specific it is the barrett model 82A1/M107.

http://www.barrettrifles.com/ - this is the offical website

佢用的不是機槍,是M4來的.......
狙擊組是不會帶機槍的.......
M4相信係人都知啦下話........