AR-15 Receiver FAQ


TGT Addict
Lifetime Member
Feb 7, 2009
Houston, TX
I am importing this from It is a Thread originally authored by xenophobe

Receiver FAQ Version 0.3 (please note this is still rough, and is not nearly finished)

I see a lot of threads asking these questions about overall quality and suggestions for which brand of receiver any particular person would recommend, so I thought I might document the aesthetics of final finish machining info into an info thread of it's own.

Who makes the best receiver? Which receiver is the best? Which receiver is the highest quality?

Of course the answer is that all of them are pretty much the same. The actual brand of receiver means little to nothing. When deciding on which receiver you should purchase you should take into consideration two factors. Price and manufacturer. Of course if price is not an object, get the receiver that has the logo or emblem that you want. I know that is superficial, but the best receiver really boils down to the one you like the best.

There are currently FOUR manufacturers that produce the majority of lower receivers for the AR market. MMS, CMT, LMT and LAR receive orders from many licensed manufacturers who obtain an ATF variance to have them cut and logo receivers on their behalf. JVP and Superior Arms cut for a couple of different companies as well, but currently I will only focus on the four main manufacturers differences.

Mega, Stag (CMT), LAR and Barrett (LMT):

Not all inclusive, and a few brands have had more than one manufacturer cut their receivers. Many companies receive CMT and LMT cuts in the white and finish them themselves. I have not seen a LAR or MMS cut that was finished by a third party company.

LMT = LMT, Lauer(old), DS Arms, PWA, Eagle, Knights Armament, Barrett, Bushmaster (?)
CMT = Stag, RRA, High Standard, Noveske (old), Century (current), Global Tactical, CLE, S&W, MGI (1st batch), Wilson Tactical, (some?) Colt, Ratworx
LAR = Grizzly, Bushmaster (L Prefix), Ameetech, (?)DPMS, CMMG, Double Star, Fulton, Spike's Tactical, Noveske (new)
MMS = Mega, Gunsmoke, Dalphon, POF (forged), Alexander Arms, Stinger, Spike's Tactical(old)
JVP = Double Star, LRB
Olympic = Olypmic, SGW, Tromix, Palmetto, Dalphon, Frankford, (old) Century
Superior = Superior Arms, Lauer (current)
Grenadier Precision
Sabre Defence (?)

There are also a number of custom cut billet lower receivers:

MGI multi-caliber
COBB multi-caliber

SOCOM Diamond (out of business?)
Sun Devil
POF - 415/416 Gen 1 (no trigger guard), Gen 2 (integral winter guard), Gen 3(integral guard + ambi bolt release)
Smith & Wesspon M&P-15PC Performance Center Model

7.62x51 receivers
POF - P-308 Gen 1 (winter trigger guard + ambi bolt release)
DPMS Panther LR-308
Fulton FAR-308 (made by DMPS)
Hesse HAR-10 (bleh... really crappy machining)

Wishful thinking:
Oberland Arms / HK 416/417 (billet)
Magpul (soon I hope)
LaRue (people have been asking.... lol)
Vltor (you never know...)
LMT (very wishful thinking...)

Not sure if RRA .308 vaporware will be forged or billet.

characteristics of the manufacturers (please note, the most typical characteristics are listed, and each manufacturer may have substantial sample variation between lots):

LMT usually leaves forge flash underneath the trigger well, and roughly cuts them between the receiver extension and pistol grip, while leaving a vertical mold flash line on the front lip of the mag well, as well as having other "fingerprint" marks... no bevel cut for the charging handle on the rear lug for the receiver extension, as well as particular mill marks in between the pivot pin tangs. They also have a 'fingerprint' cut in the receiver on the shelf, and below it where the FCG goes. Notice the diagonal mill mark on one of the pivot pin supports. Also unique is the radius in the grip tang pocket, which is not as smooth a transition as the other manufacturers.


CMT has a rounded bevel on the front of the mag well lip, generally removes the forge flash underneath the trigger well, usually offers a smooth and rounded surface between the receiver extension and pistol grip and has a unique mill mark that would be hidden by the attachment of a pistol grip. There is also a clamp mark of some sort that occurs on the top of the pivot pin lugs that LMT and LAR do not have (see 1st photo at beginning of thread).


LAR sometimes leaves forge flash underneath the trigger well, and does have a smooth flat milling mark on the round transition on the web between the receiver extension and grip. By the back of the grip tang, there is a milling mark that goes across the width of the receiver. The front of the receiver has a deep cut between the pivot pin retainers, and the front of the mag well is not always flat. The front radius to the mag well bevel is round, but the front edge sometimes shows forge flash.


MMS usually the cleanest cut, with the exception of some CMT receivers. All of the MMS receivers for Mega, POF, Gunsmoke, Dalphon and Stinger I've seen have the typical black teflon coating. Some of the receivers look absolutely perfect, others have mag wells that are cut from both sides and don't quite match up in the center. Some of them also have what look like file marks running in one direction on part of all of the receiver, and can be somewhat subdued or very noticable. I won't describe machining fingerprints, because all Mega manufactured receivers are pretty obviously made by MMS.

The forgings that CMT and LMT use are also from different manufacturers. The ribbed A2 strength on the reciever extension lug is thinner on the LMT, while the CMT is almost the full width. Mega appears to use the same forgings as LMT. All of the manufacturers seem to have some variation of mag well bevels, and those aren't primarily useful in identification.

From left to right, Mega, Stag/CMT, LAR, LMT and Barrett,

Other comparisons
All of the following photos will show from left to right; Mega, Stag, LAR, Barrett and/or LMT:

Notice the lack of a charging handle bevel on the Barrett/LMT

Notice the difference between the LMT and the larger mag well bevel of the Barrett (far right):

Trigger well forge flash clearly visible on the Barrett and LMT:


Last edited by a moderator:


TGT Addict
Lifetime Member
Feb 7, 2009
Houston, TX
From MGI:

Update for your list showing MGI Modular Lowers as CMT built lowers.
MGI only made the initial short production run at CMT.
All subsequent lowers have been machined from billet 7075-T6 with Type III Hard Anodize.

We will be producing 7075-T6 forged MGI Modular Lowers beginning in the near future, adding this to our product line, and billet types will still be available.
Custom forgings made on our specific forging dies are coming from Cerro Forge, one of the major suppliers of raw forgings for AR receivers.
postedby Ekie:
Understand that LMT machined both the early PWA and Eagle Arms lowers. A PWA and a Eagle lower from the same time period are very different. The Eagle being WAY better then the PWA.

And say CMT machined Colt lowers (never seen any evidence of this) the Colt lowers are machined to different drawings then any other.

In other words, don't matter who machined the part, what is important is what drawings are used, and how close they keep to them.

two billet manufacturers: Compass Lake Engineering (CLE) and Les Baer both make their own lowers.
it was my understanding that two entities in the country make all the raw forgings. everybody buys from them. as for billet fully machined lowers, i'm only aware of JP enterprises. CLE - i'm not sure, but i understood they were cut from forgings like nearly all the rest...


There are at least three raw lower forgings currently made.

There are a number of billet receivers on the market now...

SOCOM Diamond (out of business?)
Sun Devil
POF - 415/416 Gen 1 (no trigger guard), Gen 2 (integral winter guard), Gen 3(integral guard + ambi bolt release)
Smith & Wesspon M&P-15PC

7.62x51 receivers
POF - P-308 Gen 1 (winter trigger guard + ambi bolt release)
DPMS Panther LR-308
Fulton FAR-308 (made by DMPS)
Hesse HAR-10 (bleh... really crappy machining)

MGI multi-caliber
COBB multi-caliber

Wishful thinking:
Magpul (soon I hope)
LaRue (people have been asking....[made in Oregon])
Vltor (you never know...)
LMT (very wishful thinking...)
The Smith & Wesson Performance Center M&P-15PC is indeed a billet receiver. The rest of the S&W line are CMT cut forged receivers.

SKU: item_170293
Model: M&P15PC
Caliber: 5.56 mm NATO / .223
Capacity: 10 Rounds
Overall Length: 38.5"
Stock: Full Length, Skeletonized
Forend: Free-Floating Black Matte Anodized
Barrel Length: 20"
Barrel Twist: 1 in 8"
Weight (No Mag): 7lbs., 13 oz.
Trigger: 2-Stage Match Quality
Upper Receiver: Billet Aluminum with Robust Geometry
Lower Receiver: Billet Aluminum with Generous Magwell Chamfer
Barrel Material: Stainless Steel
Chromed Components: Bolt, Bolt Carrier, Bolt Carrier Key
Receiver Finish: Hard Coat Black Anodized
Barrel Finish: Matte Stainless
Other Features: Soft-Lined Rifle Case with Mag. Pockets, Zippered Accessory Pouch
Spikes lowers and rifles, i can tell you that the only company that has made his lower is LAR
Armalite. They are the only manufacturer I know of that forge, machine and broach there own lowers and forge and machine there own uppers hence the AR markings on the uppers.
Software Janitor:
Essential Arms has made any lowers for any other company recently. Prior to the 1994 AWB they used to make cast receivers (J-15) and then they sold that tooling to DPMS and got out of the lower business until after the AWB expired in 2004. After the AWB they started making cast lowers again (J-15-2) but they have since stopped making cast lowers and are currently making forged lowers.(J-15-F).
Knights Armament - I have been to the Knights plant and watched their machining....they cut their own lowers.

HK lowers and uppers are made from Forgings.. Been on a tour of the factory in Germany, and seen the raw forgings... They are made by another, non firearm company.


TGT Addict
Lifetime Member
Feb 7, 2009
Houston, TX
For all those of you out there who are wondering here are the facts. There are only a few actual companies that completely mill there own stuff and all the rest are subcontracted- period. I know because I am one of the actual machinists that mill the receivers and I Own the company. I have attached a list of who mills for who so you guys dont get confused.

LMT- mills for
Lauer, DS arms, PWA, Eagle, Armalite, Knights Armament, And Barrett

CMT- mills for
Stag, Rock River Arms, High standard, Noveski, Century, Global tactical, CLE, S & W, MGI, Wilson Tactical, Grenadier, Precision, Colt

LAR- mills for
Bushmaster, Ameetec, DPMS, CMMG, Double star, Fulton Armory, Spikes tactical

JVP- mills for
Double star, LRB

Mega Machine- mills for
GSE, Dalphon, POF, Alexander Arms

Olympic- mills for
SGW, Tromix, Palmetto, Dalphon, Frankford, Century

Sun devil was designed by TKS engeneering

Superior arms mills for superior.
Sabre machines their own uppers and lowers and many other parts. We also produce lowers for several other companies, but I cannot mention their names due to non-disclosure agreements.

Michael Curlett
Director of Commercial Operations
Sabre Defence Industries
BadAzzAR15 (SpikesTactical):
Just to Clear things up, Mega Never made Any lowers for us [Spikes Tactical].

We have always used LAR "which we still use", and now API as well.


TGT Addict
Lifetime Member
Feb 7, 2009
Houston, TX

High or Low Shelf AR Receivers. Who Makes What?

This is a list of companies showing who makes high shelf and who makes low shelf AR-15 lower receivers. This is in reference to RDIAS compatibility. RDIAS is Registered Drop In Auto Sear. A RDIAS can be found for much less than a registered M-16 or other AR-15 compatible registered select fire lower receiver. Here is a link that goes in to depth on the RDIAS- [url][/URL]

Green = Low shelf: DIAS compatible, shelf behind safety on inside of the receiver is 16mm deep from top of receiver

Red = High Shelf: Not DIAS compatible, shelf behind safety on inside of receiver is 14mm deep from top of receiver

Aero Precision - high shelf /low shelf

Ameetec - low shelf

Anvil Arms - low shelf

Armalite - high shelf

Bushmaster - low shelf

CMMG - low shelf

CMT - high shelf

Colt - high shelf also receiver block

Double Star - low shelf

DPMS - low shelf

DSA - high shelf

DTI (Del-Ton) - low shelf

Essential Arms - high shelf /low shelf

Fulton Armory - low shelf

LAR - low shelf

LMT - high shelf

LRB/JV Precision - low shelf

Mega - low shelf

Olympic Arms - high shelf

Rock River Arms - high shelf

Smith & Wesson - high shelf

Spike's Tactical - Bullet Selector Markings = high shelf –– Fire/Safe Selector Markings = low shelf

Stag - high shelf

Sun Devil - low shelf

Superior Arms - ?

This is the information I have so far. Please feel free to voice any corrections and continue to add to this list (please use the email function as I have no way of knowing if you posted or PM'd me since the board seems to have no notification.)



TGT Addict
Lifetime Member
Feb 7, 2009
Houston, TX
NoDak Spud, LLC:

We've always machined ours in-house.

And, we own the forging tools for most of what we make.






Greeneye Tactical
Texas Gun Forum Ad
third coast
Tyrant Designs
DK Firearms

Forum statistics

Latest member
Top Bottom