Rotating gas-check
A rotating gas-check (more commonly known as an automatic gas-check) was a copper plate that automatically attached itself to a specially designed studless projectile of rifled muzzle-loading ("RML") artillery, sealing the escape of gas between the projectile and the barrel and imparting axial rotation to the projectile. == Gallery == RML 12.5in Studless Palliser Shell Mk I with Automatic Gas-Check RML 12.5in Studless Common Shell Mk I with Automatic Gas-Check == See also == Gas-checks in British RML heavy guns Attached gas-check == Notes == == External links == 1.