KE Arms KP-15 Polymer Lower Receiver with Complete Mil-Spec FCG.

Please read this entire document prior to use.

WARNING! DO NOT Dry Fire your KP-15 without the upper in place.

Doing this can damage the receiver wall in front of the hammer.

Note: After first range session, remove buffer assembly from lower receiver by pressing down on buffer detent and pulling out buffer and spring. The cycling of the action may have removed additional plastic flash caused by the manufacturing process that was not removed during our post-weld processing. Shake out any debris or use compressed air to clear out the buffer tube.


• The KP-15 has a lifetime warranty for normal use.

• Sling Attachment points wearing out is not grounds for a free receiver replacement.

• If the receiver breaks through misuse or neglect, we will replace it ONCE for $65.00.

• Structural modifications including but not limited to: unauthorized stock shortening, removal of material, and dyeing the receiver void the warranty.

• If you intend to register your KP-15 as an NFA weapon test it thoroughly before doing so in a Title 1 Configuration. Once you Form 1 or Form 2 it, you are legally the manufacturer and we cannot service or support it as easily. Should your receiver require warranty replacement we can only replace it with a title I receiver and we are not responsible for tax stamps or NFA fees.

• Cerakoting: If you intend to have your KP-15 Cerakoted we recommend you use We Plead the 2nd ( as they are experienced in coating polymer receivers and have our authorization. The bake should be done at low temperatures

(<190 Degrees F) and with an upper in place to prevent warping.

Features Include

• Compatibility with most common AR15 uppers and lower parts kits

• Flared magwell to make reloads under stress easier to perform.

• A1 Length 13” Length of Pull (LOP) Buttstock to fit a wide range of shooters

• MLOK Slots at rear of stock for sling attachment points or run a strap through it for simple sling attachment

• Holes at the front of the stock for QD socket inserts for more sling attachment options

Technical Notes

• The KP-15 receiver uses a Carbine buffer and spring. A standard weight carbine buffer is included in your unit. Do NOT use anything other than standard carbine buffers and round springs or the JP SCSS in the KP-15.

• The front lugs where the upper receiver attaches are intentionally snug. The upper should be pushed down in place from the top between the lugs. The rear take down pin may need to be tapped in and out with a hammer depending on upper fit.

• The Take Down and Pivot Pins have the detents built into them; eliminating the spring and detent holes in the lower increases durability. Pins insert left to right. Spare pins are available from KE Arms.

• The buffer detent is held in place with a 5/64” x 1” Roll Pin

• A Mil-Spec KE Arms Fire Control Group is installed in your unit.

• The KP-15 is compatible with cassette style match triggers including the KE Arms DMR and SLT units. The retention system of these triggers with D-Clips in the bushings to retain the fire control pins makes them better suited for use in the KP-15 than other designs that require captured pins.

• The hammer pin area is wider for durability. Your receiver includes a special long hammer pin. Standard AR15 hammer pins can still be used but we offer a longer hammer pin for customers preferring a flush pin for aesthetic reasons.

• Safety selector spring and /KP-15-MilSpecdetent load from the top and then the selector is slid over them. Your receiver includes a KE Arms Optimized Mil-Spec Selector. This can be removed by placing it half way between safe and fire and pushing it out to the left. Disassembly of the fire control group should only be done by an experienced gunsmith or certified armorer.

• The KP-15 is compatible with standard AR15 uppers in calibers including .223/5.56mm NATO, .300 Blackout, 6.5mm Grendel, 6.8mm SPC; make sure you use the appropriate weight carbine buffer for your rifle to eject at 3:00-4:00.

• The KP-15 is compatible with 9mm blowback systems with a 5.4oz carbine buffer minimum. Use heavier buffers as long as your gun can cycle reliably. Failure to use this minimum buffer weight can damage the lower.

• Big Bores: .458 SOCOM, .50 Beowulf, and. 50 BMG: We will never test these calibers enough to guarantee function and durability over time; use at your own risk.

Further technical assistance can be had by e-mailing

Replacement parts and accessories can be ordered at