Advanced Polymer AR-15 Rifle Matched Upper Lower Combo X-7 Fusion Pro Receiver Set V.2

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Kaiser’s proprietary polymer receiver sets are superior to aluminum in nearly every way. Injection molded from specially formulated virgin polymers enhanced with impact modifiers and both long and short-strand glass fibers for impact and shatter resistance.

Anti-Walk Trigger Pins now included in V.2


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Advanced Polymer AR-15 Rifle Matched Upper and Lower Combo X-7 Fusion Pro Receiver Set V.2 with VLock Anti-Walk Trigger Pin System

We set out to build the world’s best performing most advanced polymer AR-15 rifle for sale in the United States drawing upon the newest technology, using space age proprietary materials and by redefining performance standards for weight and durability.  To achieve this we started by improving the foundation of the AR 15 rifle, its upper and lower receiver. Nearly all manufacturers of tactical weapons use billet aluminum in their builds which introduces a set of problems that can be avoided with alternate high tech materials.

Kaiser’s proprietary polymer receiver sets are superior to aluminum in nearly every way. Injection molded from specially formulated virgin polymers enhanced with impact modifiers and both long and short-strand glass fibers for impact and shatter resistance our harmonically optimized matched receivers are built to be stronger, weigh almost half as much and, be more accurate, require far less maintenance and keep you in shooting far longer without malfunction.

Trigger Anti-Walk Pin Install Set Now Included for easy-to-install AR-15 trigger groups

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The Most Advanced Polymer AR-15 Rifle Upper Receiver in the world


  • ● Precision injection moulded revolutionary lightweight polymer with Impact Modifiers.
  • ● Proprietary composite reinforced with short and long strand carbon fibers.
  • ● Engineered for durability and increased strength without added weight.
  • ● Lighter at nearly half the weight of aluminum receivers sets.
  • ● Eliminates harmonics from attached accessories greatly improving weapon accuracy
  • ● Flat top picatinny design for versatility in mounting optics and other enhanced components.
  • ● Rugged scratch resistant material that holds up to extreme abuse.
  • ● M4 A4 Feed Ramps feed ramps for added reliability.
  • ● Shatter and crush resistant even when shot with .308 and 7.62 rounds and repeatedly run over.
  • ● Compatible with MIL-spec lower receivers so it can be used if necessary but lines will not match.
  • ● Extreme precision tooling for better bolt carrier group fit resulting in improved accuracy.
  • ● Used by top shooters; designed for Sub Minute of Angle (MOA) accuracy
  • ● Outperforms billet aluminum receivers in high impact torture tests.
  • ● Forward Assist eliminated.


A Better Bulletproof Lower Receiver

  • Precision injection molded with anodized pin inserts for precision and enhanced durability.
  • Short and long strand carbon fiber enforced frame set in a proprietary polymer composite.
  • Lighter and far stronger than skeletonized aluminum rifle platforms.
  • Textured non slip front magwell grip surface designed for better grip and weapon control even in the most extreme conditions.
  • Beveled magwell entry allows faster magazine changes.
  • Matched to increase rigidity between upper and lower receivers.
  • Built in trigger guard eliminates the need for a flip down trigger guard.
  • No expensive coatings such as Cerakote required to protect your weapon.
  • Compatible with any mil-spec drop in trigger.
  • Compatible with all Mil Spec and most aftermarket grips.
  • Designed for dual or Ambidextrous (ambi) safety set up.


Far Better Than Aluminum

In fact it’s not really a close comparison… there are quite a few firearms companies that are doing all they can to improve upon receiver sets which usually means they cut out material to make them lighter at the expense of making them weaker, eliminate the Forward Assist to avoid force malfunctions (grunts will remember in the M-16 A2) and a few manufactures that even offer UltraMatch 7075-T6 aluminum which is 70% stronger than the commonly used 6061 aluminum and finished with milspec hardcoat anodize to a surface hardness of 60 Rockwell in an attempt to make their receivers as bulletproof as ours.  In the end, it’s still just aluminum that needs lots of oil, regular cleaning to function correctly, won’t stand up to harsh environments, can’t absorb shock and just don’t measure up in torture tests. See for yourself.


Lightweight Proprietary Composite
Our advanced polymer AR 15 Rifle upper and lowers are more durable and weigh less than any other receiver set on the market. When it comes to cutting weight we understand that ounces equal pounds and pounds equal pain… our assembled AR-15 rifle with Faxon Barrel, KSP titanium bolt carrier group, and reconfigured buffer system weighs nearly 3 lbs less than traditional systems at around just 4.5 pounds.

No Oil or Lubrication Necessary, Ever…
We’ve built the cleanest AR 15 rifle for sale on the market that requires NO OIL OR LUBE in the upper receiver. With the Kaiser Black Ice coating on a KSP titanium BCG your weapon runs without any internal lubrication. No lubrication means that sand and dirt does not stick allowing you to run tens thousands of rounds without cleaning the action of your rifle.

Salt Water Resistant – Zero Corrosion
Our composite receiver sets resist solvents, heat, cold, dirt, sand and even salt water. We even use this upper and lower receiver in our direct-gas-impingement Amphibian M4 Carbine designed for ocean operations to be completely corrosion proof and 100% reliable in all saltwater environments. If fact our Amphibian model can live underwater for 24 hours be pulled out and function flawlessly which is literally unheard of for weapon systems, even in the Navy…

No Cleaning, No Problem!
In fact we’ve run over 60,000 rounds through our test weapon without cleaning the bolt, receivers or action. Nothing sticks to our proprietary composite and when paired with our Kaiser Bolt Carrier Group with Black Ice coating your firearm stays cleaner for longer, does not require regular maintenance like standard aluminum semi automatic rifles or cleaning after every trip to the range. For field and military applications this means that soldiers can go longer in harsh terrain, arid climates, swamps and forests or any environment on earth and never wonder if their weapons are going to function when it’s time to go to work.

Impact Resistant – Dirt Devil
Our proprietary polymer does not splinter, bend or deform under pressure like aluminum receiver sets do and it resists acute force better than any other receiver set on the market. We’ve shot 5.56mm rounds through the magazine well and the rifle still functions as normal and our polymer will function even when shot with larger calibers such as .308 and 7.62mm. We’ve run over the KSP X7 repeatedly with an 8,000 lbs truck, picked it up and fired it. We’ve even poured dirt inside the upper receiver, dumped it out and fired the weapon and through all these torture tests the X-7 stayed in the fight.

Shock Absorbing Low Harmonic Composite
Our proprietary polymer receivers are lighter, stronger and they absorb shock allowing for better harmonics and improved accuracy. With our Titanium Bolt Carrier Group (BCG) we’ve stripped even more weight reduced the internal reciprocal mass. Even under the extreme stress our receivers won’t ever stress or break. For even less recoil add a 2 part polymer Spectre Buffer  system that reduces recoil and improves retargeting capability.

Shatter-Proof Lifetime Guarantee
We’re engineers, military Veterans and firearms enthusiasts with very high standards. We build our products to exceed every industry performance standard out there and offer smarter, lighter weapon systems and components for the most demanding customers in the world including top tier military units, trophy hunters, avid sportsmen and competition shooters. Our products are manufactured with pride in the United States of America and guaranteed against manufacture defects. We match our receiver sets for better performance and accuracy, inspect and test every product that leaves our facility and we stand behind our products with the industries best Lifetime Guarantee*. Now of course there are a few exceptions but unless you intentionally set out to destroy our receiver sets by perhaps running them over with a tank they’re going to hold up. , if you you put Tannerite inside a 7075-T6 billet aluminum receiver you’ve just made a paper weight  set  but generally you’re never going to have an issue with our products


Learn how to build and assemble your own custom advanced Kaiser US X7 Fusion AR-15 Polymer Rifle.








Manufacturer Kaiser.US – Kaiser Shooting Products
Finish Black / Flat Dark Earth / Grey / Olive Drab (OD) or custom
Barrel Length N/A
Caliber .223 Rem / 5.56 NATO, .300 AAC
Configuration Right Side Casing Ejection
Option N/A
MOA Sub MOA when configured
Gas Length N/A
Height N/A
Rail Length 7”
Mount N/A
Profile X-7
Reticle N/A
Co Witness N/A
Size N/A


*Custom Ejection Port Cover (EPC) required. Not Included.

*Colored/Painted parts may not match receiver sets and could be shades off

*FFL Required Before Shipping. See Restocking Policy Before Ordering.

**Returns/Exchanges are subject to a $25 restocking fee


Black, FDE, Grey, OD


X-7 BlackBird Ejection Port Cover (EPC), X-7 Lightweight Durable Polymer Ejection Port Cover (EPC)

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