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.

[lysander]

No one making 6061 lowers deserves any of your time or money.

Hmmm, almost all of the original M16 were made from 6061.

6061 if more than adequate, strength-wise.

[Hulkstr8]

I personally have used Aero and Mega. I have also seen a bunch of other lower brands out and about.

Mega is hands down the best quality stripped lower I have ever seen. Also, awesome company. Jason Curns is a badass.

Aero -I'm personally torn. All three of my Aero lowers looks sweet with anodizing. However, when I had them cerakoted pitting, dents, dings, scratched, etc all showed up. My cerakote guy says it was in the metal. I don't trust him and he could have sprayed my parts wrong or ****ed them himself. However, I have no other experience with Aero.

I stick with forged because they're stronger than billet and I'm not chasing a trailer queen at this point in my life. College and no money lol.