Looking it up the actor who plays Amos has actual military training and came from the military into acting - I thought his handling was a bit good (he is obviously processing the why not just going through the motions) even for an actor who has done a bit of weapons training. It really works with the character though.
That's pretty cool actually, was only semi serious with my Alex comment.
I'm currently past the show books wise and getting some good background on Amos...he is quickly becoming one of my favourite sci fi characters.