McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams
Taking the AR15 parts and accessories to new heightsTM
Kaiser US

Kaiser US X-7 Fusion KSP Receiver W/ Door

Kaiser US X-7 Fusion KSP Receiver W/ Door
Sign up to get notified when this product is back in stock

Availability: Out of stock




  • Lower 5.5 ounces
  • Upper 5.2 ounces
  • Match fitted from the factory for supreme fit with zero action movement.
  • Short strand and long strand fibers infused with virgin polymer not regrind.
  • Impact modifier in the polymer
  • 7071 aluminum inserts around FCG and breakdown pins W/Hard anodizing
  • 7071 aluminum buffer tube mount W/Hard anodizing
  • Textured outside surface with raised grooves on mag well for positive grip
  • Lifetime warranty.


KSP X-7 Assembly tool (sold separately)

  • KSP X-7 Assembly tool is required to be used when assembling your upper assembly. Our tool takes all strain off of the upper receiver and ensures a safe assembly
  • If you choose to not purchase our tool for assembly please note that a assembly tool must be used to ensure no damage made to the receiver when assembly.
  • Use of a “saddle” type receiver block is prohibited as these will damage a receiver during assembly, whether Polymer or aluminum due to the nature of the device.

Please note that these sets are for the advanced builder and that the barrel nut torquing must be done using ONLY the Kaiser US KSP X7 upper tool or Geissele Reaction Rod Upper assembly tool.




FFL Required Before Shipping. 


Please have your dealer email their license to or they can also fax it in. Please give us a few days to process the information.



Additional Info

Additional Info

Manufacturer Kaiser US
Finish No
Barrel Length No
Caliber No
Configuration No
Option No
Gas Length No
Height No
Rail Length No
Mount No
Profile No
Reticle No
Co Witness No
Size No


Customer Reviews (4)

Excellent especailly in tactical applicationsReview by Chad
I have been a weapons instructor for over 10 years, in both the military and civilian law enforcement. I have tested multiple AR-15 rifles. The X-7 is far beyond any other AR platform. After 1000 plus round, firing with dirt in the receiver, the weapon refused to stop working. No lubrication, no cleaning...just abuse and it continued to fire. I did not see any failures of the components. If you are looking for a lightweight, tactically sound receiver or rifle, go with the KSP X-7. I trust my life with the X-7 and it hasn't failed me yet. (Posted on 8/27/2016)
Highly Recommended!!Review by Eric
These receivers are incredibly strong and lightweight! The fit between the upper and lower is rock solid. No wiggle at all! I liked these receivers so much that I bought an additional set. The customer service at Kaiser US is phenomenal. Mike (the CEO of Kaiser) has been very easy to get a hold of and has answered all of my questions. He even called me after my 300 Blackout build to see how I was liking everything. I'm a customer for life with Kaiser, and can't wait to see the new products coming down the line. Get a set of these receivers. You won't regret it! (Posted on 8/19/2016)
Excellent ReceiverReview by Andrew
I have owned and used 2 of these for over a year and I am very impressed. Light weight, durable, all weather, and accurate. Keep it up Kaiser! (Posted on 8/18/2016)
DO NOT BUY THESE!Review by Joshua
I ordered 3 sets of these and 2 of them failed horribly! The first cracked on the back of the lower where it has a steel insert for the buffer tube and the second broke where the charging handle latches on to the upper. sent both receivers back over almost 9 months ago after i was promised a full refund and some how now i cant reach the manufacturer
do yourself a favor and stick with aluminum or just stay far from this company (Posted on 8/2/2016)

Write Your Own Review

Only registered users can write reviews. Please, log in or register

You may also be interested in the following product(s)