When it comes to ammunition, the Sub-X bullets stand in a class of their own. Designed with precision and purpose, these projectiles are crafted to deliver substantial results where they matter most—deep penetration at subsonic speeds. At the heart of each Sub-X bullet lies a lead core, engineered for maximum impact. Encasing this core is a gilding metal jacket adorned with long grooves. These strategic indentations serve more than just aesthetic appeal; they facilitate reliable expansion even at low velocities—a critical feature when dealing with subsonic rounds. The ingenuity doesn’t stop there. Each Sub-X bullet boasts a flat profile complemented by Hornady's patented Flex Tip insert nestled within its hollowpoint cavity. This combination ensures that upon contact, the bullet expands consistently and effectively, regardless of speed. For those who rely on semiautomatic weapons, rest easy knowing that cannelures provide positive case crimping. This design aspect guarantees optimal performance and reliability in your firearm platform of choice. In sum, whether you’re an experienced marksman or new to the world of firearms, trust in the engineering excellence behind Sub-X bullets for unparalleled performance below the speed of sound.