AR15 Bottom Half

AR15 Lower Receiver and Buttstock Assembly

Major Options - Cast, Forged, Polymer (Forged are best, cast are not high quality)
Various styles, Most are about the same quality

Things to consider about the AR15 Lower Receiver

Complete Lower	Serialized lower receiver built up with Trigger Parts, stock assembly, pistol grips, lower parts kit. Sometimes assembled, sometimes purchased as a kit. This is the only part regulated by the BATFE. No barrel or top end of the AR15 rifle
Stripped Lower	Serialized lower receiver made from one solid piece of material (aluminum). No internal parts. This is the only part regulated by the BATFE
Lower Parts Kit	Sold as a kit, with all the parts to assemble a stripped lower. Also makes a good spare parts kit for a complete rifle. Includes; trigger, pins, springs, standard pistol grip

AR15 Lower Receiver Parts List:

magazine catch	pivot pin	rear takedown pin
magazine catch button	bolt catch	front takedown Pivot pin
magazine catch spring	bolt catch plunger	rear takedown pin detent
Buffer Retainer Pin	bolt catch spring	front takedown pin detent
Buffer Retainer Spring	bolt catch roll pin	rear takedown pin spring
		front takedown pin spring

Our videos that feature the AR-15, M-16 and similar firearms

Top of Page

AR15 Stocks

Major Options – Fixed / Collapsible, Buffer Tube size, Sling Mounts, Storage, Lengths, Butt Pad, Cheek weld, Diameter of the Receiver Extension (Buffer Tube)
Costs $35 - 300
Tier One – High quality, tested
Other Parts Required: buffer, action spring, receiver end plate, castle nut, Butt Pad

Things to consider about AR15 Stock parts

Staking the AR15 castle nut	This is a procedure to ensure the castle nut does not unscrew. Debatable since many people don't see this as necessary
Standard vs. Heavy Buffer	The buffer is necessary for the rifle to cycle. The size and weight of the buffer can affect how the AR15 works. Changing buffers can fix or cause problems AR15 Standard Buffer CAR / M4 / Carbine Buffer Heavy Buffer Hydraulic Recoil Buffer 9mm SMG Buffer
Mil-Spec vs. Commercial Buffer Tube	Mil-Spec buffer tube is 1.148", Commercial buffer tube diameter is 1.168" Milspec is flat at the end, Commercial tubes have a slanted end (longer)
AR-15 Cheek Rests	Some stocks (VLTOR, LMT) offer cheek rests in their design, other options are add-on cheek rests that wrap around standard AR15 stocks.
AR15 recoil pads	Hardly needed on most AR15s. Can be useful for adding length to a short stock, rubber pads can also be useful to keep a good shoulder weld on gear and body armor.
AR15 stock extenders	Not usually an issue with the AR15, but these parts do exist.

AR15 Stock Parts List:

AR15 Stock (Fixed)	CAR stock	Receiver Extension / Buffer Tube
M16A1 fixed stock	M4 Stock	Mil-Spec Receiver Extension
M16A2 fixed stock	recoil buffers	Commercial Receiver Extension
AR15 Stock (Telescoping)	Buffer	castle nut
	Buffer Spring	Receiver End Plate

AR15 Parts - Stocks

Top of Page

AR15 Fire Control Parts

Major Options – Standard vs Match Triggers, Full Auto parts, manufacturer, 2 stage, Safety options (ambidextrous)
Costs $45-300
Tier One - quality/testing
Tier Two - quality of material
Tier Three -

Things to consider about AR15 Fire Control Parts

AR-15 Selector / Safety

Many styles of lever are available as well as ambidextrous options.

AR-15 Trigger

Many styles are available. AR15 hammers without the notch, like full auto hammer with the sear tail ground off

AR-15 Captive Pins

Aftermarket accessory that stop the potential issue of the trigger and hammer pins 'walking' or shifting out of position during use. Many types exist, longer pics with clips, threaded pins with bolts or washers

Captive Pins
Anti Walk Pins

AR15 Fire Control Parts List:

trigger	disconnector	hammer
single stage vs two-stage	disconnector spring	Hammer Pin
adjustable match trigger	selector	hammer spring
trigger spring	selector detent
trigger pin	selector detent spring	2-stage National Match triggers

Top of Page

AR15 Pistol Grips

Major Options – Comfort, Color, Storage
Costs ($5-50)
Other Parts Required: Grip Screw, selector spring & detent
(these may get lost while replacing)

Things to consider about AR15 Pistol Grips

AR-15 Pistol Grips	A lot of options exist. Shop around before buying, shoot with the grip you think you like. Most are solid enough, it's mostly an issue of material choice (plastic, rubber) and personal comfort . Some grips offer storage of spare parts, tools, lube, etc
Gap under the triggerguard
A2 pistol grip
Ambidextrous Pistol Grip