Doesn't matter what you have, what you can get, what mags are available where from whom for how much...doesn't matter hot hot or soft your rifle shoots, what battery it uses, how long you've been playing for, etc...
All that matters is if the particular game you are signing up for has any kit/mag/loadout restrictions. If they don't...then do whatever you want. If they do...then you are 100% expected to abide by those restrictions. If that means you don't have any mags that'll work...then go get some, or don't attend.
The only decent exception that I've seen for this is some of the WW2 re-enactment milsims. In that case more than a few of the rifles only have hicaps (real shame). Their use is tempered with the mindset of the guy who play those games. They're already switched on with why they're there so it's a usually a very solid group of guys.
Originally Posted by dutch13
So how many rounds should an Lmg gunner have in his box when in a Milsim game? Should he not only have the standard box size? I've been to milsim games where everyone is running reg caps but the lmg gunner has his box loaded to the max.
It should be posted in the game (and usually is for the games around here...usually 1000/sortie when rifles are restricted to 300/sortie). The intent is to deliver a relative volume of fire difference between an LMG and a rifle....and 3:1 is a decent ratio. There's sometimes reloading/resupply modifiers as well...i.e. cannot reload on the field, can only reload when dead, can/cannot swap ammo between weapons, etc...