The word 「grain」 is an old ordnance term for explosive powder or even for blocks of cast powders or crystals.
药柱这个词是用于炸药或者甚至用于浇注火药块或晶体块的一个古老的军械术语。
explosive powder
爆炸火药
There may still be some ignition or explosive powder left in them.
因为可能放过之后还是会有一些能够点燃或会爆炸的粉末存在。
A smokeless explosive powder consisting of nitrocellulose, nitroglycerin, and petrolatum that has been dissolved in acetone, dried, and extruded in cords.
无烟线状火药一种无烟炸药,由硝化纤维素、硝化甘油和凡士林组成,在丙酮中溶解,风干并压成绳状
explosive powder (nitroglycerin and guncotton and petrolatum) dissolved in acetone and dried and extruded in brown cords.