i'm in the process of signing up for the marine corps and was wondering what the standard arms isuued to infantry was

Those of the lowest bidder...and whatever the US Army puts into service 5-10 years prior.

USMC generally carries the same load as the US Army. M16A2, M9, M203, M249, etc. I'm sure you can run your own search for these if you want more details.

You will have gear that is heavy. And you wont have a pick up truck to throw it in when your not using it.

M16A2, M9, M203, M249 are worth thier weight in gold when you have incoming fire.

And true happiness comes directly from a belt fed weapon....