HRNDY SUBS 338ARC 307GR SUB-X 20/200

Description

Hornady’s Subsonic line exists for one specific purpose: delivering consistent terminal performance without breaking the sound barrier, and the 338 ARC loading does that with a 307-grain SUB-X bullet traveling at 1,050 feet per second. At that velocity, the round stays quiet when used with a suppressor, but the engineering challenge is making a projectile that still expands reliably when it arrives with far less kinetic energy than a supersonic load carries. That is where the SUB-X design earns its place.

The bullet uses a lead core paired with Hornady’s Flex Tip insert, which is a polymer tip seated in the hollow-point cavity. In a conventional hollow point, gel or tissue can clog the nose on entry and inhibit expansion; the Flex Tip is compressed inward by impact forces instead, initiating expansion mechanically even at the reduced velocities subsonic ammunition produces. The result is a bullet that opens predictably rather than behaving like a hard-cast slug.

The 338 ARC cartridge itself was developed for the AR-10 platform, and this subsonic loading fits that context well — a heavy, large-diameter projectile that retains meaningful sectional density downrange. Brass casings make these rounds reloadable, which matters when you are chasing precise velocity windows for subsonic consistency. Muzzle energy comes in at 752 foot-pounds, modest by centerfire rifle standards but appropriate for the application. Each box contains 20 rounds.