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

JP CTR-02
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:







Links to the manufacturers:
LMT = Lewis Machine and Tool
www.lewismachine.net

CMT= Continental Machine and Tool
www.continentalmachinetool.com
www.stagarms.com (an individual corporation that was started by CMT)

LAR = some combination of the original owner's last initials
www.larmanufacturing.com
www.largrizzly.com

MMS=Mega Machine Shop
www.megamachineshop.com (new)

JVP=JV Precision
jvprecision.net

Superior Arms
www.superiorarms.com

If there are any corrections, or requests for pics/comparisons of angles I have not yet posted, please PM me.

I'm done for now...  I'll update it with some more in a few days if there is interest...

Great post.  I appreciate the time and effort you invested in preparing this factual, informative post.

Very Nice

Anyways, all the lowers out there with the exception of Hesse/Vulcan all function the same and are all equally fine for an AR build.

This thread is only here to show the most frivolous final machining details which do not affect function or durability.  

Originally Posted By twl: Update for your list showing MGI Modular Lowers as CMT built lowers. MGI only made the initial short production run at CMT.

Thanks for the correction Tom...  Done.

excellent post
Now if they will just read it instead of asking 50 times a day "who makes the best"

Mike

Fantastic!

Nice write up.

One question - Have you ever seen any proof that CMT mills Colt lowers? I know it has been long assumed that they do but I've personally never seen any evidence of it. I ask not because I don't believe it's possible but because as you seem to note, the main 4 shops seem to have their own "tells" in the way that they are milled\finished. Having both a Colt LE lower and known CMT lowers, I can tell you that the milling just doesn't match. One spot in particular (where the buffer tube "loop" comes down and meets up with the sides of the lower) they are clearly milled completely differently.

I think people just like to assume CMT makes Colt lowers because of the proximity of the 2 companies and I think it's fair to say that CMT does supply at least some parts to Colt. I just don't believe lowers are one of those parts. If anybody has proof  to the contrary, I would love to see it

Originally Posted By BravoCompanyUSA: Nice write up and pics. Sorry, if I missed it - but do you know which ones do/don't take an RDIAS ? thanks!

the LAR ones do but not the STAGs.

Colt mills their own.

Originally Posted By cgv69: Nice write up. One question - Have you ever seen any proof that CMT mills Colt lowers? I know it has been long assumed that they do but I've personally never seen any evidence of it. I ask not because I don't believe it's possible but because as you seem to note, the main 4 shops seem to have their own "tells" in the way that they are milled\finished. Having both a Colt LE lower and known CMT lowers, I can tell you that the milling just doesn't match. One spot in particular (where the buffer tube "loop" comes down and meets up with the sides of the lower) they are clearly milled completely differently. I think people just like to assume CMT makes Colt lowers because of the proximity of the 2 companies and I think it's fair to say that CMT does supply at least some parts to Colt. I just don't believe lowers are one of those parts. If anybody has proof  to the contrary, I would love to see it

No, I have never seen proof.  Apparently there were a few, who I would assume, reputable posts stating that they have personally seen Colt rollmark dies are stored at the CMT factory.  I only included it because the information provided seemed credible, but also why I labeled Colt under CMT with the note... (some?).  

I personally don't know.  When comparing the one example of Colt that I have, it is apparent that the machining and forging are both different than the other manufacturers (which could just be because my Colt CAR-A3 is nearly 8 years old and these receivers are recent production).  This could account for both machining and forge suppliers changing over time.

It's not hard to imagine though, when Colt received a large contract order to fill that some of the parts, possibly including the milling of receivers has been outsourced.  Of course, there is no solid proof of this though.


Anyways, this isn't a really substantial post, at least concerning specs and adherence to them.  It's just a superficial rundown of finish machining and should be taken into consideration as such.

Originally Posted By xenophobe: No, I have never seen proof.  Apparently there were a few, who I would assume, reputable posts stating that they have personally seen Colt rollmark dies are stored at the CMT factory.  I only included it because the information provided seemed credible, but also why I labeled Colt under CMT with the note... (some?).

Thanks for the reply. I can see where you are coming from.

I don't doubt that Colt has had to sub out at times when orders are majorly back-logged but I'm going to guess and say that would relate mostly to Military orders (i.e. M16 or M4). Not that I've seen a ton of them but none of the Colt AR15 lowers I've seen have resembled the CMT lowers I've seen. That coupled with the fact that Colt doesn't seem overly worried about getting LE rifles out the door leads me to believe that at minimum all of their Civilian\LE lowers are made in house. Who knows?

Great post. I appreciate the time and effort you invested in preparing this factual, informative post.

+1

Thanks for the great post, it answered a lot of my questions

Thanks for doing this. It's a great reference & saves me from having to ask, "who makes .... lowers?"

Great post!

great post.  very informative and it helps answer many questions i have asked without responses.

is there something like this that exists for barrel blanks manufacturers and those folks with make the LPK's and bolts/carriers?

that would really help put it all in perspective.

thanks,




ST13

Wow, great post xenophobe.  Very informative.

I didn't know you were on here too.  

Great Post!!



LMT = LMT, Lauer(old), DS Arms, PWA, Eagle, Knights Armament, Barrett, Bushmaster (?)

Question: so who makes Bushmaster lowers....Bushmaster or LMT?

Originally Posted By septic-tank13: is there something like this that exists for barrel blanks manufacturers and those folks with make the LPK's and bolts/carriers?

Bolt carriers?  B= Bushmaster, C= Colt, L= LMT...  or is LMT marked H?  I forget...   I think DPMS are marked as well, not really sure.  With bolt carriers, it doesn't really matter much, only that the gas keys are staked properly.

Bolts?  Colt are marked MPC, FN MPF, CMT is marked MPI, and others are marked...  LMT are marked MP, if I remember correctly, though a few other bolts are marked MP as well, BCM, and a few others I'm sure....

As for the above, I honestly haven't paid as much attention, and very well could be remembering incorrectly...  Someone will come along to correct me, I'm sure.  So my apologies if I misstated something.

Originally Posted By schiffj1: Question: so who makes Bushmaster lowers....Bushmaster or LMT?

I'm not completely sure.  I've never compared a Bushmaster to either of these.  From what I understand, some of them were made by LMT, but I'm not sure if all of them have been.

Many 'manufacturers' won't say who actually makes their receivers, and I haven't really looked into it too much, only relying on what I can physically examine and in the circumstances that I can't, or don't have detailed pictures to verify leave the (?) in the list.  

I live in California, so my access to any Bushmaster is limited to finding one to look at.  They've been banned by name since 2000.  

I dont really see the point because manufacturers switch where they get their raw lowers all the time.  Sometimes from the same source sometimes from different sources.  Therefore these things can change from batch to batch.  

Know anything about Sabre lowers?

Nice write up. Thanks.

Do you know where we one could get one of those LAR lowers with that type of rollmark? Unfortunately, LAR themselves do not have any.

Love detailed threads like this.

Originally Posted By xenophobe: LMT = LMT, ..........., PWA, Eagle, .........

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.

You forgot two billet manufacturers: Compass Lake Engineering (CLE) and Les Baer both make their own lowers.

Can you rate any of these lower recievers as far as how low the tolerances are? Quality control?

Originally Posted By Ekie: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.

i agree.  mil spec is mil spec.  funny thing about it though...  mil spec or not, made all in the same place or not, some are mystically higher in cost than others.  

to take it a step further, too many of us get sucked into which one is the "best" one of the group.  some have subtle details, in terms of lower receiver build, but most are very comparable and shouldn't honestly lend themselves to a premium price over like or same LR's...

hell of a note...

it might be kind of neat to extrapolate who is made by who and associate their MSRP.  






or maybe we should leave well enough alone so we can all sleep well tonight...



again, thanks for a great post and taking the time to compare!

My most recent lowers have been Doublestar & Stag. The Doublestar has a nice flat black finish and less flaws than the rouger charcoal grey Stag. I was able to hand select the best stag out of a lot of consecutive serial numbers and even the best stag in the bunch was not as nice as the less expensive doublestar.

tag

Originally Posted By Dace: I dont really see the point because manufacturers switch where they get their raw lowers all the time.  Sometimes from the same source sometimes from different sources.  Therefore these things can change from batch to batch.

Yeah, well you can rest assured that no matter who the label is, it's likely to be manufactured by one of the four big guys.  A growing number of companies do cut their own, and as time goes on and availability from CMT, LMT, LAR and Mega decreases, you'll see more companies cutting their own.  

Originally Posted By lsujim: Do you know where we one could get one of those LAR lowers with that type of rollmark? Unfortunately, LAR themselves do not have any.

All I know is that LAR had a small batch of these released, probably about 6 months ago.  Perhaps you could call them and ask where they went, or if they plan on making any more with the honeycomb logo.  

Originally Posted By 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.

Yeah, well every manufacturer who gets a variance for a company to OEM recievers for them can request additional features or different specs.  This was pretty clear when comparing LMT cut Barrett receivers which had a different mag well bevel.

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.

Absolutely.

Originally Posted By CoffeeAddict19: You forgot two billet manufacturers: Compass Lake Engineering (CLE) and Les Baer both make their own lowers. Can you rate any of these lower recievers as far as how low the tolerances are? Quality control?

I have not seen either of these in person, so I'm sorry, I can't tell you about their aesthetic quality.  As for tolerances, every company that does not mill to Colt spec won't be completely mil-spec in dimensions, not that it would really matter to make a well functioning receiver.

Sorry, unless CLE makes a new billet receiver, it is a forged CMT cut...



I'm pretty sure the Les Baer is forged too.

Originally Posted By AR15fan: My most recent lowers have been Doublestar & Stag. The Doublestar has a nice flat black finish and less flaws than the rouger charcoal grey Stag. I was able to hand select the best stag out of a lot of consecutive serial numbers and even the best stag in the bunch was not as nice as the less expensive doublestar.

The funny thing is that a few people who actually mic'd measurements from blueprints say that the LAR cuts have the most inconsistently off-spec receivers, but not as much to actually have any effect on performance.  Go figure.

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...

JP CTR02

Nice write up!


LMT making Bushy lowers makes a hell of a lot of sense....hence the reason why the both have purple anodizing on some of their stuff.

Originally Posted By septic-tank13: 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... JP CTR02

There are at least three raw lower forgings currently made.

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

JP CTR-02
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.... lol)
Vltor (you never know...)
LMT (very wishful thinking...)

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

Originally Posted By xenophobe: Originally Posted By septic-tank13: 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... JP CTR02 There are at least three raw lower forgings currently made. There are a number of billet receivers on the market now... JP CTR-02 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.... lol) Vltor (you never know...) LMT (very wishful thinking...) Not sure if RRA .308 will be forged or billet.

You sure about S&W?  I thought they were CMT

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
http://www.smith-wesson.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=11101&langId=-1&productId=49902&tabselected=tech&isFirearm=Y&parent_category_rn=33803

Nice post. I always wanted to get a bunch of different brand and manufacture lowers and compare them.

Originally Posted By xenophobe: Originally Posted By 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. Yeah, well every manufacturer who gets a variance for a company to OEM recievers for them can request additional features or different specs.  This was pretty clear when comparing LMT cut Barrett receivers which had a different mag well bevel.

Not sure I would call the difference between a early 90's PWA and a early 90's Eagle lower a "variance".  I mean one is real close and the other is made from a bum set of specs.  

ahhhh...didn't see the "performance center" thingie.

Please excuse my ignorance. But could someone define " RDIAS" Please? Thankx in advance.

Or sticky a section that covers ALL abreviations so the ignorant questions will be a minimum

Knowing how Colt quietly made their 3rd generation SAA revolvers out of Italian made parts assembled in the U.S. and still charged $1100+ when a Uberti was $300, I wouldn't put it past them to use about anyone's forgings. The Colt today, who has survived many bankruptcies and rebounded, isn't the Colt of 20 years ago. Unions want higher wages, CEO's want bigger bonuses. They do what they can to survive in today's patent-expiration AR market. Like one user said, most of the makers have the CNC machining down to a common artform and most are solid platforms to build upon. I've had a couple of DPMS lowers lately that seem as good as anything else I've owned. I'd like to have an LMT or CMMG, but I need barrels, betamags, ammo, sights and flattop uppers, not to mention any other AR part to replace at a latter date before the Communists try to take over our country. With Colt Diamondbacks approaching $1000 or more for a .38 or .22 revolver, you'd think they'd be cranking those out again with quality for $500 and making a killing. I want a nice quality .22/.22 mag conversion kit for my AR that holds 30 rds and has a magazine that looks like a beefy AR mag, not some slender p.o.s. like a familiar maker for $60 per mag. I'd like to see Advantage Arms do one.

Originally Posted By Groundshaker: Please excuse my ignorance. But could someone define " RDIAS" Please? Thankx in advance. Or sticky a section that covers ALL abreviations so the ignorant questions will be a minimum

Registered Drop In Auto Sear

Thx Maltrose

Great post.  Ever thought about doing the uppers? I'm compiling a list of barrel manufactures AR15 and AR10.

Added Noveske to the LAR section.  Apparently his latest batch are not CMT cuts.  :(  Wish he would have gone to Mega instead.  Oh well.

I have bushmaster pics that I'll be putting up in the next week or three.

Originally Posted By constructor: Great post.  Ever thought about doing the uppers? I'm compiling a list of barrel manufactures AR15 and AR10.

No.  There is a FAQ with upper receiver markings, and only in a few circumstances will you know who actually cut an upper, and that info is already here someplace.

RRA, LMT, Noveske, Vltor, LaRue are marked by acid etching or engraving...

Colt, Bushmaster, Armalite and a couple other are marked by forge marks.

The others may or may not have forge marks, and generally aren't named.

xenophobe, do you know who is the manufacturer of Centermass Tactical "Calguns" lower?

I would like to mention something in regards to the Mega MMS receivers.  Their finish is Anodized, but the reason the appearance is different is they use a combination of aluminum oxide and glass bead blasting for surface prep. Most other MFG's uses aluminum oxide only.

You'll notice the difference in the surface if you were to put a CMT upper on an MMS lower.  

who makes DPMS?

who makes DPMS?

Hmmm....so am I to understand LMT made the old Coal Valley, IL Eagle Arms lowers?

height=8

Originally Posted By Trumpet: Know anything about Sabre lowers?

I was told by the dealer I bought my SD lower from that his contact at Sabre told him they make their own at their Nashville plant. You would think a sales rep would tell one of his dealers the truth. All I know is that it's a sweet lower.


10th post from the bottom

www.ar15.com/forums/topic.html?b=7&f=21&t=430976