Subsonic Sunday – 300 Blackout Bullet Evolution

There are many critics of 300 Blackout subsonic loads because for most shooters they don’t offer much in the way of practical performance. Sure, they sound great paired with a short barrel and a suppressor, but hunting with some of the more common loadings like a 220 gr SMK or 208 gr AMAX bullet leaves much to be desired. These bullets were designed to be fired at supersonic velocities; upon impacting a target at high speed, they expand and wound mostly through hydrostatic expansion of surrounding tissue. Without the high speeds for which they were designed, these bullets retain their shape and largely make narrow, uninspiring permanent wound cavities. Given the right circumstances they may tumble, but performance isn’t reliable.

Traditional subsonic loads like this 208 grain AMAX from CORE Ordnance often come with lackluster terminal performance.
Traditional subsonic loads like this 208 grain AMAX from CORE Ordnance often exhibit lackluster terminal performance.

As 300 Blackout has grown in popularity, so too has the selection of bullets shooters have to choose from. Barnes makes a 110 gr bullet specifically designed for the 300 Blackout cartridge, rather than using an existing .30 caliber bullet and re-purposing it, and Gemtech’s 187 gr subsonic loads also use proprietary bullets.

However, some manufacturers are going even further.

Lehigh Defense’s ever-changing product line is constantly being expanded and improved based on years of research and development. Their newest 300 Blackout loads, both in subsonic and supersonic fracturing rounds, bring brand new bullet designs unique to the marketplace. Other than G2 Research, who received a great deal of backlash from the shooting community for their over-hyped G2 RIP 9mm round, there are currently no other manufacturers offering rounds designed to break apart rather than stay together and expand upon impact.

In subsonic loads, where velocity is limited to about 1050 fps, bullet weight and design are the only factors which can affect terminal performance. Handgun bullets, which wound primarily by expanding and creating a large permanent cavity, are similarly affected. The function of the large permanent cavity is to increase the chances of hitting a vital structure by making the wound channel as wide as possible. In fracturing bullets, rather than having one large wound channel, the resulting fragments penetrate both straight through and in a radial pattern, maximizing the likelihood of striking a vital area with at least one segment of the bullet.

Lehigh Defense's new 170 grain "Lil' Prick" loads promise increased terminal performance for hunting applications.
Lehigh Defense’s new 170 grain “Lil’ Prick” load promises increased terminal performance for hunting applications in AR-platform rifles.

There has been comparatively little testing of this type of ammunition over standard expanding hollow point or polymer-tipped bullets, which leads some shooters to doubt its utility as anything more than a novelty round. Additionally, based on their unique method of operation, strict 1:1 comparisons of expanding hollow point and fracturing bullet tests may not be possible, leading to further confusion and apprehension in would-be adopters.

Terminal Effect will be testing this type of ammunition in a variety of testing mediums in the coming months. Keep an eye on this space for performance results and analysis for this new, interesting ammunition.

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