Extension有“延长”、“扩展”意,装在枪管后端的“枪管节套”译成“Barrel Extension”。 ETCH蚀刻,用酸处理方法在金属表面上刻各种图形、线条等。 武器射弹飞离枪口后的运动轨迹称外弹道,研究其的学科称“外弹道学”EXTERIOR BALLISTICS the study of the flight of projectiles Extension has “extended”, “extended” meaning, installed in the barrel of the rear “barrel section” translated as “Barrel Extension.” ETCH etching, with acid treatment method engraved on the metal surface of a variety of graphics, lines and so on. Weapon projectile flying away from the muzzle motion trajectory, said the outer ballistic, the study of its discipline called “external ballistics” EXTERIOR BALLISTICS the study of the flight of projectiles