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Extreme Shock has released a new .223 100 grain ASP (Advanced Subsonic Product) round specifically designed for civilian AR-15 modern sporting home defense assault rifles with suppressors. Extreme Shock Prez Jeff Mullins tells TTAG that the previous military-spec 127 grain ASP .223 rounds didn’t work as well as one would hope. “Because the silencers were loose-fitting, the bullet would strike the silencer on the way out. Accuracy at 100 yards was an issue. The new 100 grain ASP is far more accurate and a lot quieter. It reduces the noise levels to that of an airgun. You can hear the mechanics of the gun working. AND you can use it in civilian, suppressor-equipped AR-15s.” This was no easy task, apparently . . .

Designing subsonic ammunition is a delicate art, there is no one size fits all as with other ammunition. To achieve subsonic velocity one must change the powder, powder charge and seating depth. Extreme Shock has the only 100 grain .223 subsonic round that will fully function a military M4 and/or commercial developed AR-15s. You’ll have to [not] hear it to believe it. No modifications to the weapon. With noise comparable to a large air gun, the ASP gives the operator total stealth to achieve their objectives.  Get in, get out without being heard!

For shooters who turn to an un-suppressed .223 for home defense, Mullins recommends Extreme Shock’s AFR frangible AFR round, developed for Canadian police concerned about over-penetration in trailer parks, I kid you not. But wait! There’s a new round ‘a comin: a second generation Fang Face cartridge code-named GT. Details as soon as they land in our in-box.

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  1. Considering that .223/5.56 is not known for highly effective stopping power as it is, it is be difficult to believe that slowing it down would make it more effective. However, they did increase bullet weight.

    I would have to see some gel tests as a comparison.

      • 5.56 is designed to tumble upon impact which is the key to whatever stopping power is has. It only tumbles if it hits at a certain velocity or higher (I forget the exact speed). Slowing it down will prevent it from tumbling.

        • Actually the russian 5.45 x 39mm was designed to tumble not 5.56,If 5.56 tumbled I would have had a much easier time in Iraq.

        • Where do guys EVER come up with this crap,,,, tumbling bullets LMAO when was the last time you saw a bullet tumble in jell or tissue NEVER is when,,, even if the bullet did turn side ways do you have any idea how fast it would stop in jell or tissue !!!!!

        • LOL tumbling. How many rotations do you think a bullet will get as it zips through a body? You think the bullet is in there for a few minutes? Also, these bullets aren’t for real world usage, just for fun. I would imagine they would have less stopping power than a .22. Want proof? Shoot these at a tree, make sure you duck afterwards though.


  2. The ASP was designed for an operator to take out a sentry / guard usually head shot, or a light or dog without alerting the enemy. The user wanter the gun to function in semi or full auto mode so they would not be having to work the bolt on each individual shot. Because you have so little energy to work with the only way to make it more effective and function the gun was to make the bullet as heavy as possible. To do that we had to use Tungsten.

    The ASP is certainly not a long range round as you are only 975 FPS at the muzzle. We use compressed Tungsten powder as our core material inside a copper jacket. The .20 thou thick copper jacket gives us the malleability to get down the barrel without creating wear. The tungsten core gives us the penetration through dense bone heavy clothing into a vital to take care of business.

    Because of the low velocity it makes it very hard to impossible for the small bullet to fragment. But because of the Tungsten core we get really great penetration through clothing and soft tissue or bone. When the weapon is shouldered and fired with a suppressor is on the gun you can actually hear the mechanics of the gun then the round impacting the target.

    For the gun to function you MUST have a can on the gun. You will have to fire about 8 to 10 rounds through the barrel to coat it to help slow the bullet down. The coating does not cause any buildup as with molly nor can it be cleaned out. The coating causes no adverse effect when switching back to hi vel ammo. We have coated the barrels by shooting the ASP through the gun then we fired 4270 rounds through the gun in full auto fire. Then we put in a mag of ASP with the barrel hot the first round out the barrel was only 99o fps then 985 970 990. So it takes 10 rounds to coat and then it will be subsonic from there on out.

    We do have a gel block shot with the ASP 5.56 filmed at 40k frames a sec that if Robert has a way to post it we will be more than happy to send it to him. Please feel free to contact us at 276 926 6772 to answer any questions you might have.

    Robert, thank you for the post

    Jeff Mullins


    Extreme Shock USA

    • “For the gun to function you MUST have a can on the gun. You will have to fire about 8 to 10 rounds through the barrel to coat it to help slow the bullet down.”

      Jeff, I think you’re confusing this with first round pop on a suppressed weapon. The copper jackets on your bullets shouldn’t behave any differently than regular copper jacketed bullets. When you claim it takes 8-10 rounds to “help slow the bullet down”, I suspect what you’re experiencing is first round pop:“first+round+pop”

      On an unfired weapon, the suppressor is full of air. Unburnt powder consumes oxygen in the suppressor, causing a “pop”. Once the oxygen in the suppressor is depleted it quiets down by a few dB. Let it cool off and circulate fresh air into the can, and you’ll get another first round pop.

      As for your claims about a special coating from a plain old from a 0.020″ copper jacket… well… I hate to say it but that just sounds like more Extreme Shock BS.

      • Actually he is correct about the 8-10 rounds. They designed them that way, as stated in the article. There is a black coating that is placed on the rounds that it deposits in the barrel to help slow them down. I”m not sure how it stays there after shooting full power rounds and going back to these, but they work. It’s impressive hearing the trigger break, the hammer fall and the thud down range.

  3. Pretty cool from a suppression standpoint, and not terribly effective from a ballistic one. 100 grains at 975 fps only yields about 210 pound-feet of energy. If you have to use this ammo for self-defense, aim for the head and fire repeatedly: it has less than 1/4 the energy of the .30 Carbine.

    I believe the claims are correct about how quiet this would be when fired from a can. .45 ACP is a natural suppressed round because it’s already subsonic and gets its hitting power from its diameter and weight. However, suppressors are even more effective at reducing the noise from smaller-diameter rounds, because less of the combustion gasses escape through the smaller-caliber hole through the middle of the suppressor’s baffles. .22 Shorts are incredibly quiet from a suppressor, even an (ahem) ‘improvised’ suppressor. I wouldn’t know this firsthand, of course, since that would be illegal.

  4. This is an interesting concept, I too would love to see some independent gel testing.

    My initial thought would be that a non-expanding 100 grain .22 caliber round moving at sub-sonic speeds may penetrate adequately, but would leave you with a 22 caliber hole. 

    I expect the same noise level could be accomplished, with supierior terminal ballistics, using .45 Acp. But the idea of being able to use your fighting carbine, vs another long gun or pistol,  is very attractive.

    All that said, this bit:
    “Because the silencers were loose-fitting, the bullet would strike the silencer on the way out.”
    smells very fishy…

  5. I have used this round with great success. It works exactly as the CEO advertises. A bit costly, but I highly recommend it.

  6. I don’t know if the yaw affect of this subsonic, heavy grain bullet would pass the smell test, especially if they already know of earlier loads causing baffle strikes. I’d love to run this stuff, but don’t know if i want to loose a $1,400 can in the process. Need tons more reviews before i throw this stuff down my bore. Anyone shoot this stuff in bulk yet, through an AAC Spr/M4 can? Any noticeable issues as far as cans?

  7. Don’t know about GEL results…..but I shot a 3″ cedar post and it left a 1/2 dollar size hole out the back at about 40 yards …shooting 10rds first is just a waste of ammo and money.(these rounds are not cheap )…..shoot can wet or displace oxygen with a compressed CO2 can and tape over end of suppressor to eliminate first round pop

  8. The 5.56 mm cartridge was not designed to tumble upon impact, that is an urban legend and a total proven farce. The 5.56 cartridge has plenty of stopping power on a human and I have seen it with my own eyes from two tours in IRAQ but no it is not effective under the constraints of a NATO mandated Full Metal Jacket cartridge. Any ballistic tip will without any doubt put a man on the ground. It is about using the ammunition for the job that you are asking it to do and the 5.56×45 and .223 are very good cartridges for many applications including man stoppers. Shot placement is your second biggest factor with any caliber even a 30.06 or with 308.

  9. The Tumble Effect many are talking about started in Viet Nam Era Ar’s. The original rifle was made with a 14″ twist rate, and the 55 gr. bullets were not properly stabilized and would tumble. This was seen as a benefit to the spray and pray crowd, but after specs were raised to penetrate a helmet at 500 yards, changes had to be made and the twist rates and bullets all changed. Today’s guns with Twist rates from 7 thru 9 will handle the heaver bullets allowing better downrange performance. Sub sonic rounds are not designed for long range targets and should be the heaviest bullet you can get to the speed of sound in a given caliber. This sounds like a good loading. I will try some and see.

  10. I see your .223 extreme shock subsonic ammo. I am not seeing where to buy it. Assuming it is for sale how much is it an where do I click.

  11. I’ve used this stuff and it’s a waste of your money. It has just enough oomph to get the bolt to blow back enough to eject the case, but there’s not enough blowback to send your bolt home with enough force. It jams the next round, smashes the bullet up into the casing, making the round useless. You will literally get to shoot only half of your ammunition unless you feed your weapon one round at a time. At close to $30 per 20 rounds……or $30 for 10 usable rounds it is SO NOT WORTH THE MONEY.

  12. First of all the 5.56 or the 223 don’t tumble unless it hits bone at the right angle just like any projectile. Second a lot of terrorist would disagree that the 5.56 isn’t lethal. A 100 gr. Slow 223 sounds perfect for home defense in a short barrel rifle with a laser and light.

  13. Slow and heavy is generally good for almost nothing.
    Slow and heavy, with propeller like expansion,, is .. good for something.

    Err, aah like a broad head arrow.

    A good broad head, bleeds out it’s target, by laceration. It need only hit, cut, twirl, and penetrate to be effective, no energy transfer necessary.


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