If you're at 40 bullets in the clip and then you shoot a guy, you're still at 40. This happens with at least the SCARB and SCAR. It's not a display glitch, I actually end up being able to shoot 41 bullets out of the gun.
I'm on the PC, but have a feeling that this will translate to consoles also.
This is in the campaign, can't say whether this exists in multiplayer or not.

Edit:
See below

It's not a bug. You just had an extra bullet in the gun's chamber (don't know how it's exactly called in english) that stays there even if you reload unless you fire and run out of ammo. It should be indicated on the HUD above the ammo counter or somewhere near it.

Silly CoD misleading people as to how weapons work :\

It's 40 rounds in the mag and 1 in the chamber.
If you reload from an empty magazine you forfeit your extra bullet,
and you have to cock the weapon, which increases reload time.




Also; buy me a cat.

Silly CoD misleading people as to how weapons work :\

It's 40 rounds in the mag and 1 in the chamber.
If you reload from an empty magazine you forfeit your extra bullet,
and you have to cock the weapon, which increases reload time.




Also; buy me a cat.

You have to cock the weapon??
LMAO xD

Thanks guys, didn't notice the indicator. I think Cry1 showed full clip + 1 in this instance, didn't notice the little indicator on the HUD.