It's a logo of a pointed bullet still in it's casing. The casing is much larger than the bullet as is common in a high powered rifle. The rectangular shaped casing has a little glint of light on it making it look like it is shiny.
This is a Ammo icon. We've made it in iOS style
, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 13,300 icons, all in the same style and quality.