Actually, no. The idea was to turn the drum around so it's out of your hand/body's way when in a LS or Recon. I guess saying it's "left-handed" isn't truly accurate so to speak.
I have a quick Q concerning the drum mag. If say, in the middle of the battle you find time to reload it, but don't wish to remove it from the gun, could you dremel a slit in the side to reload in the heat of battle? Like, would the darts quite easily fall out of it?
I would have to say no. There's a little black bar that pushes up the last few dart as well as rotates the drum when you put more in. You would have to have the black pieces already lowered in order to accomplish that. I'm not saying it's impossible but probably more work than it's worth and could cause integrity issues.