The Courier

The part of Mannings was written specifically with Gary Oldman in mind.

Someone is told they are being shot at with a .51-calibre M-82 Barrett sniper rifle. The Barrett only shoots .50-calibre (.51 is a Russian weapon with different case dimensions). When we see the shooter, the rifle is obviously NOT a Barrett but, rather, a hunting-style rifle more likely shooting 7.62mm NATO ammunition.

References Over the Top (1987)