Building a reliable AR

[MachIVshooter]

Nickel boron is pretty and wipes down easier, but that's about it. I have one, and that's because Ares Armor offered them to existing customers for $79.

A lower is a lower is a lower, as long as it is 7075-T6 and properly machined. If you're paying more than ~$75 right now, you're either buying a roll mark or paying for fancy machining on a billet lower that is actually not quite as strong as a forged one, pound-for-pound.

Barrels-I don't know much about Faxon, but I will say that the video doesn't impress me. I've seen it before, and the only thing I could think about was how a standard Colt M4 being torture tested like that melted the gas tube and became a single shot, but it's barrel never let go.

Personally, I like unlined chromoly or stainless barrels. I don't have an M16 lower and I very rarely do mag dumps, so I appreciate the better accuracy of unlined barrels. For ultimate durability, yeah, a forged 4150 CL tube is best. Reality is that there are a ton of unlined 4150, 4140 and 416SS tubes out there that will shoot fine for thousands and thousands of rounds.

aligning the gas tube/gas block is a little voodooish IMHO. No problem if has a milspec sight tower but clamp on type gas blocks I still don't see how to get the hole in the barrel absolutely square over the gas block hole and have found variance in the gas tube pin length dimensions too. I build good ARs but that issue and the final torque with gas tube alignment into the upper seem kinda vague to this old engine builder.

That's far more difficult than a set screw block, unless you mean simply removing and reinstalling an existing A2 FSB. New barrels don't come drilled for pins. It ain't easy to do, and you get one chance to do it right.

Aligning the block is just not difficult. The hole on the inside of the block is about double the size of the barrel port, and it's pretty easy to see if your gas tube is straight looking along the barrel.

As for final torque, that's easy; 30 ft lbs, then continue to tighten until the barrel nut aligns with the hole in the upper. Very rarely do you need to shim or stone the upper to avoid going over the 80 ft lb max to gain alignment.

 

[ClickClickD'oh]

Hmm.. let's see now.. (I had to count) I have five ARs I've built now. They've been 100% reliable in every condition I can think of. Pouring rain, snow, coated in fine powdery dust, scorching heat, a thin layer of ice from driving around on the front of the mule in freezing fog.. they just run. I have yet to encounter the unreliable AR problem that seems to vex the internet so much.

There's a simple rule to follow that applies to everything in life. Learn the difference between cheap and inexpensive. Everything else sorts itself out.

 

[Casefull]

I find it easier for many things to get all of the parts from one source. I have built more than a few rifles from model1sales "kits" that include everything except the lower and all have worked well.

I would second that. I did 3 rifles from them and 1 pistol all in 7.62 39 and a 5.56 lightwt carbine. All are very accurate.

 

[griff383]

I have a Faxon barrel on a mix master of other parts, SAA (rumored to be made by AP) lower, spikes upper, DPMS BCG, ALG trigger, etc... and it runs like a champ with all my hand loads. I really wanted a mid 1:8 twist 16" barrel that was melonited and the fact that Faxon was cheap is what got me. I only have a few hundred rounds through it now but should be able to get out more this spring and run it through the paces

 

[.Scarecrow.]

Thanks for the info on the barrel.

 

[Ibmikey]

Scarecrow, I too have a couple of rifles built with Faxon 1/8 barrels, one mid and one carbine gas. The mid has probably two thousand rounds through it without a single malfunction. I use my rifles for plinking soda cans, steel plates and dirt clods so paper punching is a distant desire. I remember the initial sight in of this weapon at fifty yards put all shots in a group about the size if a dime. Use quality parts and your build will run forever. If you intend to go visit a war zone with your own weapon take a Daniel Defense or LWRC..

 

[C-grunt]

When looking at the barrels make sure the gas port is the correct size for the gas system (carbine/mid/rifle) and use the correct corresponding buffer.

Many companies over gas their rifles to make them "more reliable" with crap ammo. Problem is the increase in bolt carrier speed is detrimental to the system and will prematurely break bolts.

Another place to look at barrels is Sionics. They also have nitrided barrels.

 

[Creature]

Buying a complete from a reputable company is good insurance that you're getting a reliable AR.

Concur. Look at BCM or similar.

 

[Zerodefect]

Build the lower, then snap a BCM upper onto it. That's the easiest way to a reliable build.

Still:
-use a BCM bolt carrier group
-use a quality upper receiver
-mark the center of your gas block with a pencil
-mark the gas port line with a pencil and a ruler, line them up
-use good ammo, pmags, and heavy lube

 

[.Scarecrow.]

So from what some have been saying, would you guys sign off on the idea that a factory rifle will probably be more reliable than a good build?

 

[Matno]

Very little difference, and building your own is way more fun. I used a barrel from Integrity arms, which is also a 16", melonited, 1/8" twist barrel in a pencil profile. Several hundred rounds through it, and it works just fine...
Oh, and it's also mid length gas and .223 Wylde chamber. Hard to go wrong for $210.

 

[Blade First]

"I wouldn't pull a used bcg out of one rifle to put in another. I'm not sure if I understood you correctly but if that's what you are considering, don't."

You should heed part of this. Swapping a bolt carrier is not a real issue. Using a bolt assembly that has "mated" its lugs to a particular chamber during firing in one barrel might not work well in a new barrel. Check headspace if you swap.

Building an AR is almost as much fun as shooting one! If you build your upper, invest in the proper tools and blocks to avoid damage during assembly. Ruining an upper with improper assembly will cost you more in the short *and* long term.

 

[Welding Rod]

Build the lower, then snap a BCM upper onto it. That's the easiest way to a reliable build.

Still:
....
-use good ammo, pmags, and heavy lube

This is my MO.

 

[captmoto]

Very little difference, and building your own is way more fun. I used a barrel from Integrity arms, which is also a 16", melonited, 1/8" twist barrel in a pencil profile. Several hundred rounds through it, and it works just fine...
Oh, and it's also mid length gas and .223 Wylde chamber. Hard to go wrong for $210.

This is what I have found. I built a Mega Lower/PSA upper and shot it a bunch. I switched it out with a S&W MP Sport upper and shot it a bunch. I have had no problems over a couple thousand rounds. I don't but into the boutique gun hype. There are only so many companies producing barrels, uppers, lowers and bcgs. I don't think there is anybody here that really needs the so called reliability of the upper name brands, at least ant that will really talk about it.

 

[SuedePflow]

I have two WMD BCG's and they've both been great. I also like Spikes NiB BCG's. I prefer NiB over black phosphate.

 

[Fishbed77]

So from what some have been saying, would you guys sign off on the idea that a factory rifle will probably be more reliable than a good build?

This depends entirely on the factory in question. I expect a rifle from BCM, Colt, DD, LMT, Noveske, or KAC to be more reliable than a Bushmaster, DPMS, Del-Ton, or Olympic.

 

[d2wing]

From my experience the most critical part is the bolt and extractor. Buying a complete bolt with extractor from BCM solved my problems with a home built gun. Another issue is if over gassed, especially in carbine length gas tube, you may need a heavier buffer to slow things down. The barrel is critical for accuracy and some guys upgrade triggers. The rest of the rifle is pretty generic depending what features you want. I put together a Del-ton kit and it shoots great and no issues. I thought I may have to upgrade the barrel and bolt, but luckily it is very good as is.

 

[.Scarecrow.]

I've read in several articles that the main issue with unreliable builds is poor quality parts. I plan on doing the Aero upper and Lower, and possibly try to keep the barrel and BCG the same brand. I'm thinking about DD, maybe Rainier Arms, but I need to check if they have a BCG that is a good choice.

All in all, I just want to build a rifle that can be as reliable as a higher end AR like DD and Noveske, again, if that is achievable.

 

[jad0110]

Thanks for the information guys. You all seem to be in favor of a standard BCG, do you have any opinions on various so-called advanced coatings for bolts?

Nope, I've personally had 100% success with my BCM BCG (BCM complete upper). It even runs the crappiest steel case with nary an issue. Speaking of BCM, BCM "Filthy 14" proved good ARs don't have to be kept religiously clean to run properly. Though lube is important, it doesn't necessarily have to be soaked to run well either.

IMHO, the single biggest factor in making a reliable AR is selecting the right magazines for your rifle. Like 1911-pattern handguns, ARs are cursed with a plethora of crappy magazines on the market. Both my ARs run flawlessly on Magpul PMags. Most ARs do, though there are always exceptions.

 

[Bezoar]

Didnt care to create a new thread on this topic. But anyone can build an ar at home that is as good as anything Stag Arms manufactures and for less then an assembled stag arms rifle.

All you do is spend 300 for a stag arms complete basic ar lower and 549 for a complete stag arms m1 ar15-a2 upper. and youll save, before shipping and taxes, 100 dollars over the cost of purchasing the stag arms model h1.

how the extra process of stag arms combining the assembled upper and lower, and making a complete rifle and charging 100 extra is beyond me.

 

[.Scarecrow.]

I think I'm gonna go with a Rainier Slick Sided Upper, and a Rainier Lower, looking at a DD BCG, and the barrel is to be chosen.

 

[ol' scratch]

I've decided like many many others that I want to build an AR. But I won't try if it's hard to make one reliable. I have quality parts picked out from Aero Precision and a Faxon Barrel. Not sure on the BCG yet but I think I might go for WMD NiB-X. Is there really any voodoo magic to making a rugged, reliable, and accurate AR besides having the correct tools, quality parts, and following instructions properly?

Look at a mid length gas system. I have run 1500 rounds through mine without cleaning it and didn't have any malfunctions. A total of 2500 rounds and I have had a total of 2 malfunctions that I attributed to magazines. It doesn't seem to like one of my Troy Battle mags. I did start at milspec and work up from there for parts. Milspec upper with M4 feedramp, DD cold hammer forged chrome lined 16 inch mid length, Colt M16 bolt and bolt carrier (BCM is just as good. I have a BCM in my AR pistol), Spikes lower, Spec lower parts kit from Spikes, Carbine buffer and tube. I have shot WOLF in there too and my reloads.

 

[MarshallDodge]

The key to a reliable AR is in the bolt carrier group and the barrel. Next comes the correct buffer assembly. If you don't get that part right, you are going to have issues. Putting together an AR is not difficult but you really should understand how they work.

Like others have said, go with a reputable company that has a track record.

 

[C-grunt]

Didnt care to create a new thread on this topic. But anyone can build an ar at home that is as good as anything Stag Arms manufactures and for less then an assembled stag arms rifle.

All you do is spend 300 for a stag arms complete basic ar lower and 549 for a complete stag arms m1 ar15-a2 upper. and youll save, before shipping and taxes, 100 dollars over the cost of purchasing the stag arms model h1.

how the extra process of stag arms combining the assembled upper and lower, and making a complete rifle and charging 100 extra is beyond me.

There is a federal tax for complete rifles. That is the difference in price you see when buying a complete rifle versus a lower and upper separate from the same company.

 

[C-grunt]

Very little difference, and building your own is way more fun. I used a barrel from Integrity arms, which is also a 16", melonited, 1/8" twist barrel in a pencil profile. Several hundred rounds through it, and it works just fine...
Oh, and it's also mid length gas and .223 Wylde chamber. Hard to go wrong for $210.

I disagree.

While it is entirely possible to build a very reliable AR-15 from miscellaneous parts it is not the same as buying from a reputable company.

Many companies out there use different sized gas ports for their barrels. Especially mid lengths as there is no official size. When you buy a barrel from XYZ company do you know its port size? Do you have the correct buffer to go along with the correct port size? Do you need to go to a heavier buffer to compensate for an overly large port?

A company, we will use BCM for example, extensively tests their parts to make sure they work correctly with the other parts. Spring rates are tested. The final product designs are measured to assure proper bolt carrier speed, proper feeding, proper ejection, etc...

An AR that is built using parts from different manufacturers runs the risk of having those parts not wanting to work together properly. An out of spec gun might run fine with normal shooting. Hell it might run fine when pushed hard. However I would bet that when pushed hard the problems would start to surface.

Ive seen this happen with major manufacturers who like to cut corners. Owning them recreationally they work fine. When subjected to hard duty use they start to fail.

The best analogy I can think of is a car engine. I can order a parts kit and watch instructional videos and put together a Chevy small block in my garage. I have enough mechanical knowledge that I could built a running motor with good instruction. However I have no delusions that I would build a more reliable motor than a company that makes those motors for a living.

My advice to the OP..... If you are asking these questions Im assuming you are not a well versed AR armorer. If you want the most reliable rifle you can get buy a complete rifle (or a complete upper and lower separately) from a company thats known for building fighting rifles. Colt, BCM, Daniel Defense, KAC, Noveske, etc..

However if you want to build your rifle make sure the parts you buy are correctly spec'd. Dont just see someone stating their parts are "milspec" and assume they are. A lot of them in fact are not. Do some research and make sure you buy parts that work together correctly and buy quality parts.