| GENE SLOVERS US NAVY PAGES MOUTH PLUGS |
| 1431. Mouth plugs.—With separate case ammunition, it was formerly the practice to seal the case with a brass mouth cup. This was in the form of a brass bowl, the sides of which fitted inside of the case. The object in its use was twofold, first to form a gas seal in the case to prevent escape of the gases past the rotating band, also to keep gases from breaking cases by outside pressure on the case, before the projectile started to engrave the band in the grooves, and, second, to make the case an air-tight container for the powder charge. It has been shown that the gas escape is insufficient to require this form of seal, and as the brass mouth cup had a tendency to break up and boomerang back, endangering personnel, cork plugs have been substituted. |