Aviator Arms FAQ

Tell me more about the X-1.

The X-1 from Aviator Arms is a recoil device designed to build a smaller, more compact AR-15 pistol.  Its design removes the buffer tube, buffer, and recoil spring from the back of the lower receiver, and relocates them in a more compact form to the top of the upper receiver. The X-1 replaces only these three components and does not permanently alter the firearm in any way. The X-1 is compatible with all standard mil-spec components and most upgraded components as well. 

An X-1 equipped pistol will be approximately 7" shorter than a standard pistol build and is designed to be fired un-shouldered like any other semi-auto pistol.  If additional shooting support is desired, we have had very good results using a single point sling during our range testing.

The X-1 has been tested and will work with the following:

  • .223 suppressed and unsuppressed
  • .556 
  • 300BLK subsonic suppressed and supersonic unsuppressed


Do I need an Adjustable Gas Block?

An adjustable gas block is required for any subsonic or suppressed round and highly encouraged for any build to ensure optimal performance as any pistol length gas system tends to be over-gassed.


What is the minimum barrel length I can build with the X-1?

The minimum barrel length to avoid powder fouling of chamber on .223/5.56 = 6.5”

300BLK functions well down to 4.75” barrel


What sights do you recommend I use with the X-1?

We recommend either low profile irons with use of foreword rail riser, or pistol style micro reflex direct mount to X-1 spring tube pic rail.


Are there parts that the X-1 will not pair with?

The X-1 has been tested and will work with almost all mil spec AR build parts.  It will not work with the AeroPrecision M4E1 upper due to non-standard pic rail arrangement, however it will work with other AeroPrecision uppers that use Mil-Spec pic rail arrangement, or any other Mil-Spec upper.