The Metal Gear Solid series of games are pretty realistic when it comes to guns, with a few exceptions though. MGS isnt really a shoot everything that moves type of game though.
It CAN be played that way though, on easier levels, if you want to.
MGS3 is refreshingly realistic
for a videogame, which means it still has some irritating problems.
For one thing, the mosin nagant should have about 3x the rate of fire it does. I've never seen anybody that couldn't work a bolt action faster than that.
Good things, though:
The modeling of the M16 and AK are practically perfect. The sights on the AK suck, the recoil makes full auto pretty much useless at anything except very close range; probably the best part of the game. My roomate (who knows nothing of guns) had his AK on semi the whole time, I asked him why, his response was "Full auto makes a lot of noise but you really can't hit ****".
The m16 is much better on both sights and recoil. I do believe the m16 requires more COM hits to put down bad guys too.
You can hear the character take the safety off the 1911 when you prepare to fire, and put it back on.
All guns hold the proper amount of ammo.
You can hold a guard up with an empty gun, but if you press the fire button he will hear the click and pwn you so fast.
You REALLY can't hit anything at all with a scoped sniper rifle unless you lie down.
I'll give healthy lisence on things like the tactical reload, the absurd amount of COM hits it takes to put people down, etc. which may be seen as necessary to gameplay, but when it comes to the actual guns, some little things are just hard to forgive.