In modern times, the t80 and t90 both require its barrel lifted the t34 also required it
To reload your gun in the game simply press 'r'. So easy a caveman can do it.
When th ammo in the sentry gun reaches 0, then you can reload it. To reload, walk on top of the sentry gun and press the F key. I'm not sure if you can reload it when there is still ammo in it though, but you can try. When you reach the rank Colonel, once you set up a sentry gun, you will have double ammo for the sentry gun, and you can reload it faster.
there is a button at the top of the screen that says reload click it to reload
shoot outsid the screen that should reload your gun.
Chamber
you have to get the USP pistol and empty the clip and when you reload it will "flip" the gun
default is R. goto options keyboard and look for reload key
Yes, the operator does it.
space bar
you cant
It is a matter of seconds. In a WW2 era tank it is a manual process. A well trained loader of the era can reload the gun in under 10 seconds. Modern (present day) tanks equipped with autoloaders can fire again less than 3 seconds after the previous shot - even while moving at high speed across rough terrain. In contrast WW2 era tanks could only fire while standing still, later models could do so while moving slowly.
The steel part on the top of the gun where the gun can eject the bullet/reload.