The museum's Lancaster is a late Mark X and has a electrically-controlled Martin 250 CE 23A turret equipped with two .50 caliber machine guns. The front FN-5A turret was armed with two .303 caliber machine guns.
Avro 683
Lancaster Mk.X
The tail turret was the most important defensive position and carried the heaviest armament. Most Lancasters carried the Nash and Thompson FN20 tail turret with four .303 Browning Mk.II guns. The turret, carried 2,000 rounds per gun, compared with the front turret's 1,000 rounds per gun.