ball ammunition; standard bullet
Military term for ordinary full-metal-jacket or standard-issue ammunition, as opposed to tracer, armor-piercing, or other specialty rounds.
We use ball ammunition in training.
They loaded a mix of ball and tracer rounds.
徹甲弾 is armor-piercing ammunition designed to penetrate armor, whereas 普通弾 is ordinary ball ammunition.
Compound of 普通 (ordinary) and 弾 (bullet, round). The term is a straightforward calque of English 'ball ammunition' or 'ball round'.