memes

Depends on the game. To name a game with a similar mechanic, Rainbow Six 3: Raven Shield (back when R6 was still a tactical shooter franchise with a fair amount of realism) had you cycle through your magazines.

For example, let's say you have three magazines of ten rounds each. You fire three shots and reload. Now your magazines look as follows:

• 10 rd. (loaded)
• 10 rd.
• 7 rd.

Now you fire five shots and reload again. Now they look like this:

• 10 rd. (loaded)
• 7 rd.
• 5 rd.

That's plausible enough to count as realistic but not as punishing as throwing your mag away every time you reload. It also turns reloading into an interesting decision beyond making you unable to fire while the animation plays: If you reload frequently, you initially have a fresh magazine but you also put a half-empty mag into the queue where it might end up in your gun when you least expect it.

Note that RVS did not allow you to pick up guns or ammo, even if they're identical to what you're fielding. If you bring 30 rounds then that's how many chances you get to shoot someone during the mission, period.