Are there any rules out there specifying how many hands it takes to use various weapons?

I'm just wondering if it's possible to use two assault rifles, one in each hand, if I can handle all the recoil.

Sure there is... and: not really... but ask the GM.

First: in Arsenal page 162. It states you can use a two-handed fireweapon with one hand for a -2 at firing. That is everything greater than an SMG.

Secondly: Arsenal page 163 it says some completely weird stuff about shooting with two weapons. Something about only using two (small) weapons with simple actions unless using full burst... Umm... yeah?

Of course you split your dicepool between both attacks and recoil counts for both weapons added. Also you may get -2 for two targets (or more if you going on to spreading the love) And you cannot use laserpointer or smartlink. And may get -2 for your off-hand. (If you don't have ambidexterity)

So.. technically it may or may not be possible... but since its cool your GM should allow it *g*. (But you won't hit anything of course)

Good enough for me. Thank you.