AR lower receivers - variance in quality between brands?

[Eta-Carinae]

I have an old Bushmaster XM-15 complete lower that is California 1989 AWB compliant (i.e., A1 stock) purchased back when it was unclear if any kind of AR would be available after the California single-evil ban. It was a panic purchase to get a serial number in on the California assault weapon registration requirement to get a grandfather clause document.

After I get my MA requirements all settled, it'll get relocated with the rest of my collection. At that point I'll have to keep in mind manufacturing and assembly standards for makers of uppers, but what about the parts I already have: ignoring the individual pieces on the quality spectrum for the rest of the parts (stock, recoil spring and buffer, trigger group, bolt release, and pins), how should I consider this Bushmaster receiver on the quality scale compared to other available stripped lowers?

And, within a given product class (cast, forged aluminum, forged steel), are there variances in quality that need to be considered or brands that are better than others when comparing apples to apples on manufacturing techniques?

 

[vellnueve]

Pretty much all lowers are the same. Bushmaster is solid.

 

[Raoul Duke]

Here's a list of which brands are made by which producers.

 

[99si/mass]

Have bushmaster, lmt and olympic arms love the bushy and lmt have had minor fitting issues with the oly though.

 

[PatMcD]

I've only heard of problems with Olympic.

 

[Rob]

Here's a list of which brands are made by which producers.

Nice list. Don't know how I missed that.

Looks like I'm all LAR Manufacturing. I have no complaints.

 

[MassMark]

I've only heard of problems with Olympic.

Yes, there have been some machining issues with Olympic - especially in the mag well. I think a lot has to do with inspection/rejection as well. Some companies, (like Olympic) may have a lower standard of QC where others will inspect lower receivers more vigorously and reject those that do not meet their standards....

 

[Skald]

Pretty much all lowers are the same. Bushmaster is solid.

Not all of them are the same. Yes they look the same but each has differing specs they want. A place like DPMS is notorious for out of spec lowers. S&W had some lowers that had problems with the mag drop.

There are a ton of great stripped lowers on the market but I would stay away from Olympic and DPMS and a few others.

Not all the 'must' have lowers are costly. Stag/CMT puts out a great lower at an affordable cost, as well as Anvil Arms and some others.

 

[7.62x39]

I've done builds on two Olympics, two Stags and a Bushmaster. The only hic-up I had with any of them was on the Bushy. The hole for the detent pin spring was not drilled deep enough. Easy fix though.

 

[vellnueve]

Not all of them are the same. Yes they look the same but each has differing specs they want. A place like DPMS is notorious for out of spec lowers. S&W had some lowers that had problems with the mag drop.

There are a ton of great stripped lowers on the market but I would stay away from Olympic and DPMS and a few others.

Not all the 'must' have lowers are costly. Stag/CMT puts out a great lower at an affordable cost, as well as Anvil Arms and some others.

Hmm, I've seen problems with other parts from Olympic and DPMS (and a few others like Hesse) but it seems like the lowers are usually good enough to build a perfectly good rifle.

 

[copterdoctor]

I built up two DPMS rifles. No problems with assembly. Function and accuracy is good.
I'm now setting up to build an Essential Arms lower. We'll see if it's as good as DPMS.

 

[Skald]

Hmm, I've seen problems with other parts from Olympic and DPMS (and a few others like Hesse) but it seems like the lowers are usually good enough to build a perfectly good rifle.

Never said you couldn't build one, but its a gamble if your going to get that lower that is out of spec. I have not heard many bad things about things about DPMS lowers (at least compared to there LPKs). The one I did hear horror stories for lowers was Superior Arms. One poor kid spent money on a lower that was so out of spec that it was a glorified paper weight (magazine well not up to proper dimensions as well as the holes being either to small or two big for the needed pins).

My next lower is probably going to be a Spikes Tactical with the Pictogram with Color Fill option. Also I soooooooo want a Sun Devil stripped lower for the CDI factor.

Out of all the lower manufacturers the two I would NEVER touch are Superior and Olympic. DPMS is just a choice as I want a certain level of quality in my AR parts which DPMS doesn't give on a consistent basis.

 

[terraformer]

Never said you couldn't build one, but its a gamble if your going to get that lower that is out of spec. I have not heard many bad things about things about DPMS lowers (at least compared to there LPKs). The one I did hear horror stories for lowers was Superior Arms. One poor kid spent money on a lower that was so out of spec that it was a glorified paper weight (magazine well not up to proper dimensions as well as the holes being either to small or two big for the needed pins).

My next lower is probably going to be a Spikes Tactical with the Pictogram with Color Fill option. Also I soooooooo want a Sun Devil stripped lower for the CDI factor.

Out of all the lower manufacturers the two I would NEVER touch are Superior and Olympic. DPMS is just a choice as I want a certain level of quality in my AR parts which DPMS doesn't give on a consistent basis.

I can testify to Superior. The mag well on mine is undersized. Other than that, it is not bad. But then again, what part do you use the most???

 

[vellnueve]

I have one rifle built on a DPMS. No issues with anything, and it's my SHTF. The two Anvils from the NES buy have also been perfect. The other four rifles I have extensive experience using are two RRAs and two Colts, and haven't had an issue with either.

 

[Skald]

I have one rifle built on a DPMS. No issues with anything, and it's my SHTF. The two Anvils from the NES buy have also been perfect. The other four rifles I have extensive experience using are two RRAs and two Colts, and haven't had an issue with either.

How many rounds? Run it hard or just casual range time? Take any tactical courses with it?

Not to be a prick, but if all you have done is normal shooting with it and not really test its tolerances etc then how sure are you that it will hold up as a SHTF gun?

 

[vellnueve]

It's got a couple hundred through it with no hiccups. I haven't run any tactical courses with it because I can't afford the ammo. Maybe some day...

I'm not sure it'll hold up, but I'd feel the same way about any rifle. That's why I have backups.

 

[Mike1911]

I don't know anything about the manufacturing of lowers, uppers and complete firearms but isn't there certain tolerances and specs that are to maintained? Are there no quality control checks?

I never knew that the major manufacturers of AR's have other companies make their major parts. I THOUGHT that say, Bushmaster, DPMS, etc. made their own major components and just bought springs, pins and other parts.

I guess it's like buying a computer from say, Dell. They buy the parts, put it together, and slap their name on it.

I learned something today.

 

[terraformer]

I don't know anything about the manufacturing of lowers, uppers and complete firearms but isn't there certain tolerances and specs that are to maintained? Are there no quality control checks?

I never knew that the major manufacturers of AR's have other companies make their major parts. I THOUGHT that say, Bushmaster, DPMS, etc. made their own major components and just bought springs, pins and other parts.

I guess it's like buying a computer from say, Dell. They buy the parts, put it together, and slap their name on it.

I learned something today.

They also design the part. Someone else mills it out, but DPMS can't just show up and get Oly's design, they have to go to the mill with design in hand and what most people here take issue with on Superiors, et al; are the design specs like small holes, big holes, mis-sized mag wells etc;

 

[vellnueve]

Yeah, but what Skald is saying that each company has its own tolerances for every part. Lowers are made by a few companies (and uppers forged by even a smaller number of companies) and then other companies do the finished machining.

Even Colt doesn't make all their own parts.

 

[Joe R.]

Vellnueve, I've run my RRA lower thru a class and trust it enough to run it as a SHTF rifle. It's still a hobby rifle compared to an LMT, Colt, etc. but will work enough for my uses. I'd make the change of the uppers to the RRA lower to at least make sure of a little better quality. Still, you never know what lurks in the hearts of lowers...

A couple of hundred rounds isn't enough to check out your AR for dependability. The upper should run with no problems under courses of fire. The lower should be able to run all of your mags, lock the bolt back, and not have any problems with the trigger. The only ways to check this are under actual conditions or training under those conditions. Anything else besides that is just making you feel good.

Joe R<

 

[terraformer]

Yeah, but what Skald is saying that each company has its own tolerances for every part. Lowers are made by a few companies (and uppers forged by even a smaller number of companies) and then other companies do the finished machining.

Even Colt doesn't make all their own parts.

Finishing may explain holes out of whack or other imperfections due to over an zealous line tech, but an undersized mag well is a straight up design problem.

 

[vellnueve]

Vellnueve, I've run my RRA lower thru a class and trust it enough to run it as a SHTF rifle. It's still a hobby rifle compared to an LMT, Colt, etc. but will work enough for my uses. I'd make the change of the uppers to the RRA lower to at least make sure of a little better quality. Still, you never know what lurks in the hearts of lowers...

A couple of hundred rounds isn't enough to check out your AR for dependability. The upper should run with no problems under courses of fire. The lower should be able to run all of your mags, lock the bolt back, and not have any problems with the trigger. The only ways to check this are under actual conditions or training under those conditions. Anything else besides that is just making you feel good.

Joe R<

Like I said, I'm not that concerned about it. Maybe at some point it does fail me, but right now I'm more than happy with its performance. There's a difference between testing for function and paranoia.

And that's just my SHTF rifle. My SRFHTF rifle is the M1A.

Finishing may explain holes out of whack or other imperfections due to over an zealous line tech, but an undersized mag well is a straight up design problem.

I'm pretty sure the mag wells are finished by machining as well. For example, one of my Anvils is great, but the other is just a little bit tighter on the mags (they still drop, though)

 

[terraformer]

I'm pretty sure the mag wells are finished by machining as well. For example, one of my Anvils is great, but the other is just a little bit tighter on the mags (they still drop, though)

They could also be design revisions between parts but I doubt either of us could figure that out since even sequential serial numbers can be from different lots if the OEM mixed lots. I doubt a large shop like colt would do that, but I can see a smaller shop doing that because mfg QA is generally not as established in smaller shops.

 

[matt1956]

I'll give a big 2 thumbs up for the RRA lower/rifle.

I have mine as my SHTF gun and it was surely run through its paces.

went to a tactical class with it and the weather conditions sucked... it was freaking cold and shitty rain the whole time.

the gun was as soaked as i was and i was shooting shitty wolf ammo... only had 1 jam up the whole time that i have discovered was the mag, not the rifle. And I easily put about 400+ rounds down range that day. not to mention the countless range trips this work horse goes on.

 

[Joe R.]

Like I said, I'm not that concerned about it. Maybe at some point it does fail me, but right now I'm more than happy with its performance. There's a difference between testing for function and paranoia.

Not paranoia. Finding out that your rifle, or any rifle, isn't right when the SHTF is too late to fix it. Save the money for a tactical rifle class and learn how to use it for it's purpose it was made for! It's better to have a training event and have it tested their to fix what is wrong. I have enough ammo for 1 or 2 classes ( Federal XM-193 in the old boxes ) but need to get into shape to go. You will learn what works and what doesn't in 2 days. I learned more in that class than I did for half of my military training! I had 1 malfunction that took a little more grunt to clear and didn't have a problem after that. Come to find out that the chunk I saw coming out of the ejection port was part of the firing pin retaining pin that broke. I found that cleaning the rifle the next day - I pay attention to this area now more than I did then.

Joe R.

 

[Skald]

I'll give a big 2 thumbs up for the RRA lower/rifle.

I have mine as my SHTF gun and it was surely run through its paces.

went to a tactical class with it and the weather conditions sucked... it was freaking cold and shitty rain the whole time.

the gun was as soaked as i was and i was shooting shitty wolf ammo... only had 1 jam up the whole time that i have discovered was the mag, not the rifle. And I easily put about 400+ rounds down range that day. not to mention the countless range trips this work horse goes on.

You have a newer or older RRA? Curious because I had an earlier one and it was awesome as far as quality goes.

 

[vellnueve]

Not a fan of the apparent dremeled M4 feedramps that have shown up on some RRAs.