First one is the M2 Browning (50 cal BMG) that I mentioned, 17,149 joules of projectile energy. Fires full auto or single shot by paddle triggers(by the thumbs). From what I remember, what used to be the longest recorded kill was done with one of these.
Second one looks like 3 M134 Dillons. The feed chains look too wide to be a XM214. This fires 7.62 rounds at up to 3,900 rounds per minute.. each.
