Haha I've seen that user name hundreds of times and For the first time I see what it means. Before it was just a mishmash of letters and numbers to my eyes. D'oh!
It actually started as a play on words of 1 shot, 1 kill back in my PC gaming days. It seems to have stuck and I still have a few old friends and acquaitances call me 'one shot' for short. It was actually funny hearing a few guys say 'Go one shot!' at Short Track. Wish it helped me climb faster! Less shots and beer, more training I think...