imagine you are playing Assault-Ops, it's a 3v1 situation, 3 guys vs you... you come around the corner sprinting, look to your right and there is a guy, staring you directly in the eyes with an AK-47 pointed between your eyes, he looks down the scope, then you quickly grab your P90 and blast his head off, but you used your whole magazine! better reload, but wait a minute, you hear shooting from your left, UH OH, you duck behind a crate nearby, and begin to reload, you take off the clip, grab a new one, slide it on, and pull the cocker, right as it reaches the end of the slide, 2 guys comes around the side of the crate, you switch to your deagle, and make a skillful headshot on one of them, it was your last shot though! UH OH, you switch to P90 and try to shoot... but it didn't reload... RIP you.
lol sorry I explained that so poorly, basically when in RT if you don't watch the WHOLE animation it doesn't reload, even if you pull the "cocker" (I don't think it's called that but it's the thing that you pull after you replace the magazine) and switch weapons immediately. hopefully A-OPS won't feature this. c: