In the Savage Worlds - Deluxe Edition core book (and in any other books I've read) the only time I've seen it specified that a weapon was 2 handed was with Melee weapons. With ranged weapons, not a single one has the "2-handed" note, and I can't find additional information anywhere. Obviously it wouldn't make sense to wield a .50 caliber sniper rifle with one hand (or dual wielded) but what about an Uzi? If a character was inhumanly strong (Necessary Evil setting) then it seems reasonable that they could do something like hold an M2 Browning in either hand.
It sounds like it's completely at DM discretion whether a player could use something with one hand. Am I just missing something?