Largo's gun appears to be a Lahti L-39.
a55 = ass
Piro tweets: I'll amuse you with two things this morning. First, this was part of my research for todays comic: http://tinyurl.com/6kmrej
Piro tweets: and here's the first frame to amuse everyone. I had way too much fun researching stuffs today: http://tinyurl.com/5ga4mj