Subsonic Controlled Fracturing Bullet from Lehigh Defense

Lehigh Defense bullet

Lehigh Defense announced a new 176 grain bullet in its Controlled Fracturing line of projectiles. The new bullet is designed for subsonic use in 300 BLK, 300 Whisper and .308 Winchester cartridges.

These all copper bullets have pre-stressed fracture points with a brass center post sort of like a floating, over sized HydraShok post. When the bullet strikes flesh, it violently expands creating a large wound channel. The petals of the expanded bullet break off while the center core continues to penetrate. The company states the core will penetrate a minimum of 18″ while the petals will go at least 10″.

Lehigh Defense is careful to note that these are not frangible rounds made of compressed, powdered metal, but instead machined from bar stock. Since expansion does not occur until and unless they strike something like flesh, they are safe to use in gun with an attached sound suppressor.

The company lists the preferred velocity range of these bullets as 750 – 1,200 fps. For optimum stabilization in .308 Win, the company also recommends a 1:10″ twist on barrels of any length with a velocity of 1,040 fps. No specific guidance for 300 BLK/Whisper is given for these.

Unlike the typical advice given to handloaders to start with a minimum charge and work up, Lehigh Defense suggests starting with a higher charge and working down. They recommend this to avoid getting a monolithic bullet stuck in the rifle bore.

Richard Johnson

An advocate of gun proliferation zones, Richard is a long time shooter, former cop and internet entrepreneur. Among the many places he calls home is


  • Ryfyle

    A machined round? sounds super pricey and decadent. Could we just make the VSS 9mm round?

    • Dracon1201

      That’s basically what this is.

  • Christopher Wallace

    much wow, such expense.

    yep i definitely want to pay over a dollar a round for .45acp power

    BUT BUT BUT it can go 50 more yards…. shut up nerds

    • CommonSense23

      45ACP power with the subsonics. Which is forgetting the whole reason 300BLK really exist. To be able to go from subs to super without a mag change.

      • Christopher Wallace


      • 35Whelan

        Actually a 45 AR style DI carbine can fire very warm 45 Super loads, approaching 45 Colt levels. So, you can be chucking 300 grain bullets at 1300 fps into and through just about anything. All using the same magazine. If you want more range, I believe 90-100g projectiles are available in .452 diameter. Should be able to push them up around 2000 fps. Lots of options.

        • AlDeLarge

          That sounds like a nightmare to get it to cycle reliably.

          • 35Whelan

            JP silent buffer assembly with assortment of springs allows tuning as needed. Can also simply add buffer weight for heavier loads as needed. Higher pressure rounds actually cycle the action better in the 45 DI carbine. If anything, cheap weak loads are where problems will generally manifest.

            For a carbine that can penetrate the largest game, create wide wound channels (with proper bullets), and double as a short-medium range urban defense platform with superb barrier penetration, this is a very good option. Also very modular, compatible with all AR accessories and rail setups.

          • AlDeLarge

            Just about any round can cycle reliably if it’s the only round you use. I’m talking about using subs and supers in the same gun without readjusting the gas block or changing buffer weights. That’s the main point of 300 BLK.

            I’ve changed nothing on mine, first built as a pistol with a ridiculous muzzle brake. It came with the upper. Then a blast director. And now it’s an SBR with a suppressor. I’ve only ever had magazine-related issues. Subs don’t like to feed from full 30 round Pmags.

            Now that I’m rethinking it, a heavier buffer would probably work better. But I’m sure it would work for subs and supers.

    • Budogunner

      This is why I have a 9mm upper. SOOOOOO much cheaper to shoot suppressed subsonic than my .300 BLK upper.

  • Sianmink

    176 is darn light for .300 subsonic. Would have preferred to see a number starting with 2.

    • Swarf

      0.0251429 pounds?

      • DIR911911 .

        0.03 US Dollar

    • Graham2

      Would an extra 24 grains really make much difference to you? A 176 grain projectile isn’t exactly an airgun pellet! 168 grain 30 cal subs can be very effective.

      • DIR911911 .

        but wouldn’t a 230 grain be even better? that’s what the russians use for their subsonic version. that extra weight means more powder behind the bullet to get it to speed , meaning even more energy on target.

        • JSmath

          Heavier bullet means less powder. They’re inversely proportional.

          Heavier bullet means longer **duration** in the barrel, which is why lighter, thinner bullets of a given caliber do not pair as well with shorter barrels of the weapons they’re made for.

    • JSmath

      I think they didn’t target a grain weight but merely came to one after taking max chamberable length dimension, then designing a bullet that could be efficiently machined and work as intended. Good BC + Essentially shattering on penetration into flesh.

  • Swarf

    Oh sure, and I’ll get deleted if I make a joke.

    • iksnilol

      Uncircumsized male genitalia ?

      • Graham2

        Hey you, stop peaking through my window!

  • MindMelder

    Lehigh makes some great bullets. I have their controlled chaos in 556 and what is does to gell is wildly impressive. Catastrophic wound channel with gaping damage.

    • 35Whelan

      Tried any on coyotes or other pests? Results?

  • alex waits

    Looks like a sabot.

  • iksnilol

    Y’know, I am tired of this subsonic stopping power game.

    Just get a suppressed M79 or something, I mean, it’s subsonic and guaranteed to stop things in its tracks. Or a slingshot and handgrenades, smaller and lighter than any SBR (without the paperwork for an SBR or silencer).

    • Dougscamo

      An arrow is quite effective….and very subsonic….

      • iksnilol


        That’s awfully boring… and the stopping power is horrible. How can you even compare a 40mm high explosive grenade with a silly pointy stick with some “fabulous” feathers on it?

        • Dougscamo

          Fall on one and see if the outcome is any different….just a touch slower….

          • iksnilol

            Eh, well, anythings a [redacted] if you’re brave enough 😉

          • Dougscamo

            And YOU said stopping power….I’m shocked!!!!….

        • JSmath

          HE? I thought we were just talking about lobbing training cement rounds at animals with the intent to bludgeon them to death from 50-100yds.

    • noob

      how do you silence a hand grenade?

      • iksnilol

        Well nobody hears where it was shot from. Can’t trace you then.

  • Blake

    Anyone else think these look a whole lot like RCA audio jack adapters?

    • DIR911911 .

      they’ll jack you up alright

  • gordon

    Isn’t this information more than a month old? It is not even among the 3 most recent Lehigh offerings and those were put in the catalog weeks ago.

  • Henry Reed

    I sent The Chopping Block some Lehigh Controlled Chaos in 5.56 and .300 BLK. This looks like their most promising load and I’m looking forward to how they perform in gel and barriers.

  • sb

    how is this not armor piercing ammo according to 18 USC section 921(a)(17)(B)?

    • DIR911911 .

      because deer don’t wear armor ???

    • AlDeLarge

      The ATF hasn’t decided 300 BLK “may be used in a handgun” … yet?

  • DIR911911 .

    why would the recommendations be any different for 300blk vs 308 ? same bullet , size and mission. just curious , not trying to be a smart ass . . . this time

  • noob

    Gel videos please!

    also can the brass core penetrate armor?