Years ago an American soldier asked me why we cock the gun before we remove the belt, as a cocking handle slip could fire a round. Didn't know then, don't know now. Even more mystifying is the cock then remove mag on both LMGs compare with remove mag then cock on SLR & L85 (SMG & pistol too for that matter). Please note I'm not asking what the correct drill is, I know that, but why it is. All I can think of is to ensure the working parts are to the rear whether you've already cocked it or not and I can't see that really matters. Asked here 'cos it's probably a matter of history. edit - Cock isn't always a dirty word y'know.