Facebook might hate freedom, but it's still going strong here.
if your a "sniper" and looking for a backup, i would say go with something really small and light. If your a "sniper" you will want to be concealed and not so bulky. So like an MP5 K i would imagine, would be great. a drum is big and bulky and will slow you down, plus if its a side arm, you should only be using it very rarely.