My guess would be something chambering a .308 caliber round ... I do believe your picture is of a Barret .50 caliber and that WILL stop a truck ... or light armoured vehicles.

Now what Trey needs for his "fast attack" boat is "Ma Duece" .... maybe a pair of twin "Ma Dueces" .... its hard to beat Mr John Browning's .50 caliber Machine Gun, +70 years of military service, and a range of +3000yds .....

.... no-one argues with "Ma"

Harry