I know you all are excited about by new rant.
I did a comparison of a Vietnam Era M16 with a 20 round magazine and another with a 30 round magazine, and the one in Black Ops looks like a 20 round variant, even though the in-game weapon carries 30 rounds.
If you look at Hudson's M16 on the M16 page, it does have the 20 round, but he has to shoot 30 rounds before reloading.
And when Extended Mags is put on the weapon in MP, it takes the model of a 30 round magazine and yet it holds 45 rounds (I know, I use it in combination with a surpressor).
Any particular reason for this?