Blitzkrieg Components has partnered with KynShot to develop a game-changing new 9mm AR-15 hydraulic buffer. Taming the violent direct blowback forces in the 9mm system, it turns your 9mm AR carbine into the smooth-running, soft-recoiling, fast-shooting precision tool it always wanted to be. Most impressive: It comes with a limited warranty: 10 years or one million rounds.

The Blitzkrieg Components AR-15 Hydraulic Buffer is designed for AR-15 rifles with a collapsible stock. It has a hydraulically dampened piston which absorbs the shock from the bolt carrier’s rearward motion. It prevents bolt bounce as the new cartridge is chambered. Hydraulics will prolong the service life of your parts and still outlast your gun.

One warm summer night in 1981, Marine and genius firearms designer Maxwell Atchisson was drinking a Coors beer, listening to “Hit Me With Your Best Shot” by Pat Benatar thinking about the XM177E1. (How many times have you ever seen Marine and genius in the same sentence?)

Colt XM-177E2
Colt XM-177E2

While the XM177’s CDI factor (Chicks Dig It) was off the charts, it wasted a lot of energy as flash and noise. It got very dirty quickly and the ballistics on the 10.5 inch barrel left a lot to be desired. As the song changed to “Free Bird” he realized that the XM177 needed to be redesigned in 9mm. (Warning: This historical reenactment may not be completely accurate.) He was a genius and could just do stuff like that. His 9mm gun was a closed-bolt, simple blowback-operated submachine gun.


The simplicity of blowback guns has always interested me. Since most of these designs are full auto, most shooters don’t encounter them. I thought this quote regarding blowback-operated guns was profound:


“In the larger sense, blowback might well be considered a special form of gas operation. This is reasonable because the cartridge case may be conceived of as a sort of piston driven by the powder gases. Actually, blowback involves so many special problems that it is best considered to be in a class by itself.” —George M. Chinn

Atchisson’s blowback system consisted of a heavy bolt resting against the base of the 9mm cartridge case, and a heavy buffer and recoil spring that is compressed by the kinetic energy of the bolt when it is thrown back in recoil. The stored energy of the compressed spring drives the bolt forward into the firing position. This eliminates the whole gas system, allowing the use of very short barrels. For close quarters, it had all the energy it needed in a small, low-recoil package with the great ergonomics of the M-16. A 10.5-inch barrel is the sweet spot for 9mm, giving near optimum energy.

Colt’s lead designer, Henry Tatro, took over the project and in 1985, Colt introduced the 9mm SMG. Colt was more interested in parts commonality with the M-16 than innovation. They came up with a rough, mass-produced product still sold by Colt today. The Marine Corps adopted the 10.5-inch barrel model for the Fleet Antiterrorism Security Teams (FAST), and it was used by DOE, DEA, U.S. Marshals Service, and the U.S. Diplomatic Security Service. The Bahamas, Bangladesh, Malaysia, and Panama also fielded the SMG.

Colt SMG Model RO635
Colt SMG Model RO635

There were several problems with the SMG. A special heavy black buffer was designed to keep the cyclic rate below 1,000 rpm; a standard 5.56mm buffer would run at 1,250 rpm. Because the direct-blowback design created such high bolt speeds, the trigger and hammer pins were upgraded to nickel-plated stainless steel.

A large deflector was added to deflect the extra gases away from the shooter’s face. The magazine well is fitted with an adapter to accept modified Israeli UZI magazines. The Colt magazines have narrow feed lips. They are very hard to load, prone to double feeds, and wear quickly.

Inspired by the SMG, several companies have re-invented the AR in 9mm and addressed the magazine issue by adopting the solid and available Glock mags. With the problem of the magazines solved, now we must move on to excessive bolt speed.

The blowback operation of the 9mm AR-15 drives a very heavy bolt (normally 16 ounces) much harder than a standard AR-15 BCG. The energy of the 9mm bolt needs to be dampened to reduce wear, reduce recoil and minimize sight movement. Hydraulic shock absorption is very effective—it is science.

The Blitzkrieg buffer shoots softer and runs quieter than any conventional AR buffer. Its weight and length have been optimized for the 9mm application so it runs reliably, softens recoil and stops the bolt just behind the bolt catch using any 9mm ammo type. It dampens bolt impact for a soft landing which completely eliminates spring vibration and noise.

Blitzkrieg Components is a small, veteran-owned company. They are easy to talk to and eager to share information with interested customers. The owner, Brian C. Hormberg, studied manufacturing in college and joined the Marines. In the kind of happy-ending story we all love, after 20 years shooting rifles, pistols, and tank guns, Brian and his wife established Blitzkrieg Components to develop innovative, high-quality products for serious shooters.

I talked to Brian and figured out there was something to his buffer. He sent one out and I rushed home to throw it into a gun and get to the range. As promised, installation was simple—you just replace the buffer. For 9mm ARs with 14.5″ or 16″ barrels, Blitzkrieg recommends using a JP Enterprises AR-10 spring. For an unsuppressed SBR or pistol with a shorter barrel, they suggest a SPRINCO Orange AR-10 carbine spring.

Installation video

I gathered my equipment for the test. I had an assortment of 9mm ammo, but I mostly used Georgia Arms 9MM Luger 115gr Plated Total Metal Jacket. It is great ammo at a fair price. I used LULA loaders for the Colt mags and the Glock. Some people ridicule loaders, but when you are loading 1000 rounds at a time, it makes a difference. I had plenty of Glock factory mags of various sizes and some 33 rounders of uncertain Asian origin. The SMG mags were all Colt.

9mm ARs used:

  • Colt SMG with a 10.5-inch barrel with AimPoint T-1 mico
  • JP Rifle JPGMR-13™ 9mm with a 14.5-inch pinned barrel with Trijicon Reflex Sight
  • Lone Wolf G9 Carbine with a 16” upper with Aimpoint Comp-M

I started with a Colt SMG as the baseline. With a Colt recoil spring and a black Colt buffer, split times between rounds are almost exactly .09 seconds. That is 666 rounds a minute. Installing the Blitzkrieg with the stock Colt recoil spring had no measurable difference in cyclic rate. I did notice a reduction in muzzle climb and better target transition. There was a slight reduction in felt recoil.


I had several springs available, but the best match across all the guns was the Sprinco ORANGE .308 Carbine spring. A simple test is to load a magazine with one round, load the SMG, and fire. If the bolt locks back, your bolt is going all the way back. If it fails to lock, your buffer and spring are probably too heavy.


I strongly recommend this buffer and spring combination.


The Lone Wolf G9 uses a proprietary buffer which runs great.  I used it with their high quality 9mm and .40 caliber uppers.  Because the system is direct blowback, I am concerned that over the life of the gun, the recoil forces will cause rapid wear.  The Blitzkrieg buffer and Orange Sprinco spring made it run like a Swiss watch—timing everything perfectly while reducing felt recoil.

JP Rifle JPGMR-13
JP Rifle JPGMR-13

The JP Rifle JPGMR-13 did not like some of the conventional buffers I tried, but it ran flawlessly with the Blitzkrieg buffer and Orange Sprinco spring. It lacks a bolt hold-open; you have to run it like an MP5 or AK.

When I was at MP5-instructor school, I asked the HK guy why there was no bolt hold-open. He replied, “You don’t want the enemy to know your gun is empty.” I thought about that for a minute and said, “Shouldn’t at least one of us know the gun is empty?” Aggressive tactical reloads and 33-round mags help a lot. The worst sound in the world is a click when you really wanted a bang.

The Colt magazines are very hard to load without a LULA. As said before, they are prone to rapid wear and double feeds because of the narrow feed lips. I ran every size 9mm Glock magazine in the catalog from 10 to 33 rounds without complaint. Even old magazines from the Clinton era work great if you change the springs. The aftermarket magazines were hit or miss with a lot of jamming—don’t waste your money.

I ran over 2000 rounds of every stray 9mm round I could find through all the guns I had. All of them, even +P loads, cycled fine, but you could sure feel the difference in recoil. I have come to realize that many of the problems I had attributed to magazines or just bad karma were timing issues eliminated by the Blitzkrieg Hydraulic Buffer.

My overall impression was that this product yields less felt recoil and smoother operation, producing less movement of the sights during recoil for faster shot-to-shot recovery time. It keeps the rifle in battery slightly longer, so the extractor has an easier time doing its job, and has more inertia when bringing the bolt forward—ensuring more reliable chambering of the next round.

Constructed from 17-4 stainless steel, the Blitzkrieg Components 9mm AR-15 Hydraulic Buffer is built to outlast your gun. The hydraulic seal and porting was designed using highly advanced automotive technology. Quality materials and precise manufacturing make Blitzkrieg confident enough to offer a 10 year, one-million-round warranty. I am currently looking for sponsors to provide the ammo to test that warranty.

I didn’t shoot the buffer long enough to see the impact on parts wear, but it makes sense that dampening energy will reduce bolt-carrier speed, reduce wear on parts, reduce shock and vibration to optics, and suppress bolt bounce. I believe that this buffer will more than pay for itself many times over in saved repairs and reduced aggravation.

Blitzkrieg Components 9mm AR-15 Hydraulic Buffer

  • Price: $124.95
  • Product Code: KYN-RB5007
  • Buffer Length: 3.90″ (when compressed)
  • Buffer Weight: 6.0 ounces
  • Machined 17-4 stainless steel buffer body
  • Most recoil reduction of any 9mm buffer made paired with the right spring
  • Smoothest running 9mm buffer available
  • Faster follow-up shots
  • Quiet buffer operation
  • No spring noise
9mm AR pistol with a Sig arm brace
9mm AR pistol with a Sig arm brace

Blitzkrieg also makes a pistol buffer kit. Because it lacks a gas system, the 9mm AR makes for a very reliable pistol. Near maximum velocity is reached at 10.5 inches, so a 16-inch barrel is overkill.

Featured photo courtesy of Lone Wolf Distributors