LOWER RECEIVERS QUALITY

[Mullins223]

Hi all.
I know that this question has probably been asked before, but I went through the search and couldn't find any answer directly pertained.

I'm in the process of building my second AR and I'd like to know if there is really any difference between the various manufactures out there concerning lower receivers. Now I know that a lot if not most of the outfits hang their name & logo on receivers made by someone else. But is there really any difference between them.
And I'm not interested in getting involved with a billet lower so let's not go there.
For example, there are T 6061 and T 7075 forgings. Is there a standard for this or are the 7075 only carried by the better names? Or is 7075 the standard.
We all know that certain name are "supposed" to be better, but are they? For example, I read recently that Andersons are just as good as the others but are cheaper because Anderson doesn't advertise as much and therefore has to sell for less.
It seems to me that what it comes down to is that all the pins fit the right way; not to tight and not too lose.

Opinions gentlemen...

Thanks to those that answer

[Eric D.]

Not all lowers are created equal. 7075 T6 is the standard - it is much stronger than 6061. No one making 6061 lowers deserves any of your time or money. Just like everything else it comes down to the reputation and documented end user experiences of the company in question. Colt (of course), BCM, Daniel Defense, Aero, Mega, to name a few, all make good lowers and other products in general. I don't think many people here will recommend an Anderson lower - No personal experience with them but I've followed some threads where its obvious they are not well liked.

As you mentioned many companies outsource production and simply have their logo stamped on the finished product. CMT does a lot of machine work for the consumer firearms industry. The thing about contracted machine shop work is that the shop will produce the product to whatever specs they are given and that information is almost never made public. That's where the difference lies. Reputable companies are going to adhere to the specs set forth in the orignal Colt TDP as best they can, others will cut corners where they can (anywhere they can) to save a few pennies. So again, it comes down to reputation.

You can find drawings for lower receivers online, don't know how accurate they all are, but it will give you an idea of the degree of complexity. Granted, in today's world there are things much more complicated but there are plenty of areas to go worng, not just pin fitment.

[Mullins223]

Eric - thanks for the info.

[HeruMew]

I got a TN Arms Polymer lower, very cheap. Like, 30 bucks.

But, it doesn't work with Polymer mags. Milspec/Metal mags only due to mag catch being set to far back for structural integrity. (I think).

Coulda just gotten a dud that was off a few tenths, but I dunno.

I have anderson lowers that fit all my parts and kits just fine. I just hate their stupid 3/4 screws.

[GH41]

Many things can affect the cost of a receiver set. Some shops run their tooling harder and longer. Combined with no quality control you will see bad ones. Some only spot check 1 of X# pieces produced. Others like BCM inspect every single receiver. With the difference in cost between a known receiver and a cheap one being small compared to the build cost why would you take a chance.

[NYH1]

I've used Stag, Colt and Anderson (just one) lowers. I've used Stag, Colt and BCM uppers. All have been fine except the Anderson lower. It took work to get the BCM lower parts kit to fit. So it's just a range toy.

The BCM upper was the tightest upper I ever used. We had to mildly cool the Colt SOCOM barrel and mildly warm the BCM upper. I looked around online and the tight upper/barrel fit seemed to be normal.

Just my experience, NYH1.

[Eric D.]

BCM does that by design on their uppers. BCM uppers are unique because they are made exclusively by a shop BCM controls. There was a time they were buying up upper receivers in the commercial marketplace and had a reject rate as high as 50%. That should say something.

I've used Stag, Colt and Anderson (just one) lowers. I've used Stag, Colt and BCM uppers. All have been fine except the Anderson lower. It took work to get the BCM lower parts kit to fit. So it's just a range toy.

The BCM upper was the tightest upper I ever used. We had to mildly cool the Colt SOCOM barrel and mildly warm the BCM upper. I looked around online and the tight upper/barrel fit seemed to be normal.

Just my experience, NYH1.

[NYH1]

BCM does that by design on their uppers. BCM uppers are unique because they are made exclusively by a shop BCM controls. There was a time they were buying up upper receivers in the commercial marketplace and had a reject rate as high as 50%. That should say something.

I figured as much. All the BCM products we use have been nothing but great, couldn't be happier with their stuff!

NYH1.

[Biggy]

I paid a premium for a couple of these lowers a few years ago, but I am fine with that, with no regrets, I wanted what I wanted. They were worth it to me, but to most people they would not be. They are like a fine balanced and blue printed racing engine, *everthing* is to spec and spot on, with no surprises.

http://www.tacticallink.com/Battle-A...15-LR-EDM.html

Battle Arms Development Gen 2 Premium Forged AR15 Lower Receiver

Not all forged lower receivers are created equal. Battle Arms development set out to create the best forged lower receiver on the market at a level not done before in a production level for forged lowers.

Specifications:
Quality Aerospace 7075-T6 Aluminum Alloy Raw Forging (No Seconds or Improperly Heat Treated Forgings)
Ultra Precise Wire EDM Cut Magwell for Dimensional Consistency and Reliability (Not CNC or Broached)
3D High Power, Deep Laser Engraved Logo, Text and Fire Markings Prior to Anodization. Razor Sharp Image Quality (No Logo Blurr or Inconsistent Engraving Depths)
Precision Reamed to Size Holes for the Pivot Pin, Takedown Pin, Hammer Pin, Trigger Pin, and Safety Selector (Not Simply Drilled to Size)
Receiver Extension Thread Machined with High Precision and Low Stress Helical Threading (Not Drilled and Tapped)
Bead Blast & Acid Etch Immediately Prior to Anodizing for Uniform Finish and to Avoid Oxidation and Contamination
MIL-A-8625F, Type III, Class 2, Hard Anodized Flat Black Finish
Compatible with TDP/Mil Standard AR Lower Receiver Parts
Dimensional Accuracy Inspection
All sharp edges de-burred by hand
Legacy M16/M4 Selector Stops Removed and Blended Smooth to Receiver (No Trace of Selector Stops Remain)
Pictograph Selector Markings Properly Marked for 90° Safety or BAD-ASS-ST / BAD-CASS-ST Short Throw Ambidextrous Safety Selectors
Receiver Safety Selector Hole Machined with Relief Cut for Battle Arms Development "SHORT THROW" Ambidextrous Safety Selectors
Multi Caliber Marking for Build Versatility
Deep Magwell Bevel Cut
All Components, material, and packaging made in the USA

[tom12.7]

Within a good process standpoint, do you believe that this above process is a better solution than some other options available? The density for some surfaces and interactions could be done in other ways. We can look into this further, If you'd want to pursue that.