I've seen a few videos on the History Channel (sniper documentaries), Military Channel(Top Sniper II) and YouTube (http://www.youtube.com/watch?v=t3cJYsey15U) of USMC and Army snipers. The thing that really stands out to me is that <span style="text-decoration: underline">some </span>Marine snipers cycle their bolt MUCH faster than that of Army snipers. Are they trained to do this, and what's the reason behind it?