Here are 5 best AR 15 lower parts kit (LPK) to buy to finish your AR15 stripped lower receiver builds. These parts don't need to be super fancy, and here are the ones we recommend after years of AR15 building experience.
Most lower parts kits here come without the buffer assembly or trigger.
Best Lower Parts Kit AR15
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PSA MOE Lower Parts Kit - Best Basic Lower Parts Kit
Palmetto State Armory is a company that focuses on civilian firearm ownership, and most AR15 components they made are in house without middle man, which means cheaper price for you.
Their AR15 lower parts kit include all the parts you need including hammer springs, trigger and pistol grip to finish the main lower receiver without the buffer system.
This budget lower parts kit is for any AR15 builders who need everything to finish their lower receiver without the buffer assembly or the buttstock.
- Includes Magpul MOE Pistol grip and trigger guard.
- Includes Palmetto State Armory Defender Classic AR 15 Lower Parts Kit.
- The Defender Classic AR 15 Lower Parts Kit includes a polished fire control group in nickel and a standard safety
If you want a complete lower parts kit with buffer and stock, please click here
Geissele Ultra Duty AR 15 Lower Parts Kit - Includes Large Bolt Catch Paddle
Geissele is a reputable manufacturer that makes top tier aftermarket AR15 triggers, and they also have multiple product lines such as the URGI and Super Duty Rifles that mil-spec AR builders love.
This is their AR15 lower parts kit minus the trigger components and pistol grip. This kit is for anyone who may already have a drop in trigger or a grip they would like to use.
- The same lower receiver parts used on SOPMOD URGI and all Super Duty Rifle line
- All key parts are made of stainless steel, which is strong and won't rust easily.
- The kit includes the Maritime Bolt Catch, which has rough surfaces and big buttons, and the Ambidextrous Super Configurable Safety, which lets you change the safety levers and feels good to use.
- The Ultra Duty LPK comes with the Ultra Precision Trigger Guard, which is made of strong aluminum and looks nice.
Also check out the Super Duty build kit without the serialized lower receiver here
CMC Lower Parts Kit - Includes A Great Drop In Trigger
CMC makes great drop in AR15 triggers and their lower parts kits come at a decent price.This is their Single Stage, Small Pin, 3.5lb pull trigger lower parts kit without the pistol grip. (Flat trigger option available here)
This kit is recommended for builders who want a basic lower receiver parts kit with an outstanding trigger right out of the box.
Aero Precision M5 Lower Parts Kit - Most Popular
This AR 15 lower build kit includes all parts need to complete a M5 lower receiver build. Instead of a boring A2 style pistol grip, this one comes with a Magpul MOE SL grip, trigger guard and with a PDW style grip angle.
ALG Defense Lower Parts Kit - Includes ACT Trigger
This ALG AR 15 lower build kit includes all the parts required to finish a lower receiver build, and the ACT (Advanced Combat Trigger) is smoother and sharper than a stock trigger. The sear geometry has not been changed from the standard profile so the high reliability that the stock trigger is known for is unchanged.
Trigger and hammer are made from true 8620 alloy steel military specification castings, correctly carburized, quenched and tempered for high surface hardness.
A full force hammer spring is used for positive ignition of all type of ammunition. Pull weight is above the U.S. Military minimum pull weight of 5.5lbs but does not reach near the upper limit of 9.5lbs. Generally, the pull weight is about 6.0lbs."
AR15 Lower Receiver Parts List
- Bolt Catch Coiled Pin
- Bolt Catch Plunger
- Bolt Catch Spring
- Buffer Retainer
- Buffer Retainer Spring
- Fire Selector Hex Key (Radian Ambi Fire Selector)
- Magazine Catch (Magpul BAD Lever)
- Magazine Release Button
- Magazine Release Spring
- Maritime Bolt Catch Safety Detent
- Safety Detent Spring Takedown Pin & Pivot Pin Detents
- Takedown Pin & Pivot Pin Springs
- Trigger guard
- Trigger bow
- Trigger hammer
- Trigger Sear
- Trigger Guard Pin
- Takedown Pin
- Takedown Pivot Pin