Forced air circulation channel, ensuring the even temperature in the working chamber.
强迫式循环风道，确保工作室温度均匀。
2
Chamber-loading trace, rifling trace, chamber throat trace and bullet pulling brace are the four major bullet traces which formed on the bullet after its movement circulation.
进膛痕迹、线膛痕迹、坡膛痕迹、拔弹痕迹是弹头经枪械运动循环后，在弹头上形成的四种主要的弹头痕迹。
3
Alloy steel fan for air circulation and chamber temperature uniformity.