Building a reliable AR

[Ibmikey]

Unless your intent is to fire great multitudes of ammo through the rifle in a short amount of time failures are just not commonplace in today's rifles using quality parts. I have a pile of AR's and although I shoot many thousands of rounds in a year they are spread amongst multiple rifles, so only a few of the favorites meet high round count criteria. I built most of the rifles and with the exception of a broken firing pin the rifles run flawlessly...buy quality barrels, BCG's and magazines, use an H2 buffer (in most cases) and you will be GTG.

 

[Matno]

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?

An AR that is built using parts from different manufacturers runs the risk of having those parts not wanting to work together properly....

Do some research and make sure you buy parts that work together correctly and buy quality parts.

That's the most fun part - doing lots of research. I'd be willing to bet that I spent more time researching my parts than most people ever will spend shooting a particular gun. Not everyone likes that, but for me it's interesting learning.

 

[.Scarecrow.]

I have a Daniel Defense and the gas port seems to measure around .08. I plan on finding out my gas port diameter for the barrel I will buy. I also plan on trying different buffer weights and doing research in that area. In terms of buffer spring, as of now I want to try one from Daniel Defense, but that's kind of my fallback if you will.

I still have a good ways to go.

By the way I checked out Sionics barrels and they look pretty sweet.

 

[B!ngoFuelUSN]

Ahhh ya beat me to it C-grunt.
Creating a reliable mechanical device (in this case an AR) requires a good and proven design, quality parts, proper assembly but the piece that is rarely acknowledged is that it must be built and tested as a system.
Unlike the joke about helicopters which are 'a loose collection of parts flying in formation' the integration of the selected parts and the rigorous system tuning, testing and tuning again, repeated many times through hundreds of thousands of rounds through all types of weather and circumstances is the way you build a rifle as a system.
And just choosing to get mil-spec parts doesn't help much with the systems design issue but it does narrow down to a more likely working set for the system.
But unless you are willing to do the work that quality manufacturers do to design and test a rifle system, a home build will likely not be as good. And it will be hard to know how good it is because a single version shot by one user isn't going to provide lot of interesting testing data.
I've built a few AR's (5.56 and 300 BLK, conventional and restructured to comply with CA's exempt rules precluding the need for a bullet button or a 10 round limited mag) and most have worked out fine. One in particular is excellent the very first time I took it to the range and other than swapping a barrel (.223 to .300 BLK) it just kept going.
On the other hand if I was going to bet my life on a gun for war, for SHTF, HP and other real-world-decisions use cases, I'd call DD (first on my list) or Stag (only because I'm left handed), Colt, Scar16 and H&K (or just get a Sig 556) to deliver a real life quality firearm. I would use their basic and upgraded designs as a bet-my-life model. No question. For the guns I assemble, they work great at the range and out hunting but I would not trust them for anything bigger than critters that are small enough that they won't turn and charge at you and a failed gun yields the risk of death.
But that's just me.
So if you want to go through the building experience to learn more about AR's and to get the pride and building and shooting your own creation then by all means go for it. However if you are looking for a real 'bet your life' gun, find a make model from one of the companies (and there are a few more, but shipping high volumes and/or shipping to our military is key to know that they've been shaken down in large number to prove their quality.
B

 

[.Scarecrow.]

While philosophies like that appear to be sound, and make sense. I have yet to hear from the guy who's build didn't run well. I also want to mention that if I am to do something like copy my DD build closely, what exactly would I be able to do incorrectly to make the gun unreliable. What exactly can conflict between quality parts if they are chosen correctly, and by chosen correctly I mean: Gas-port diameter to buffer relationship, properly machined, tested, and heat treated bolt, quality made 11595E barrel, that sort of thing.

 

[Blade First]

"An AR that is built using parts from different manufacturers runs the risk of having those parts not wanting to work together properly...." -- C-grunt

Well, sure...there is a risk if you don't choose well. Otherwise, your advice is arrant nonsense. It's the sort of speculation that makes mechanical engineers grind their teeth.

Well-made parts of proper materials machined within spec are going to "work together". Why would they not?!

"But unless you are willing to do the work that quality manufacturers do to design and test a rifle system, a home build will likely not be as good." -- BingoFuelUSN

And why not? It's not like there aren't decades of experience disproving your contention.

"And it will be hard to know how good it is because a single version shot by one user isn't going to provide lot of interesting testing data."

How exactly do you think that data bases are built? Really, sir, this sort of "reasoning" is amateurish at best and harmful at its worst.

We're building ARs...not helicopters.

 

[.Scarecrow.]

While that was a kinda brunt, Blade First, that's pretty much what I'm talking about.

 

[Quentin]

I forget who said it first but here goes:
"The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together."

Of course none of us actually builds an AR, we gather together parts and assemble. So a better description is "designing a custom AR". I like to start with a nice 7075-T6 lower and don't mind paying an extra $35-50 for smooth finish, flared magwell and respected rollmark (like S&W). I get a quality M4 receiver extension kit with H buffer from BCM or occasionally from PSA when they have a good one on sale. So far I've gone with a BCM, Daniel Defense or PSA Premium barreled upper and added lots of Magpul.

It's hard to go wrong that way. A BCM or DD upper on your own lower should be as reliable as a complete BCM or DD as long as you do the lower right using quality parts. And you can still pat yourself on the back and say it's your "build".

 

[IndianaBoy]

I have built 4 ARs for myself and helped various friends with another dozen or so.

Some of these are FAR outside of the original design parameters with lightened bolt carriers, lightened buffers, captive buffers, adjustable gas blocks, match triggers.... etc.

Others are as close to the original design as possible, or as close to "mil-spec" (which is a minimum standard anyway) as you can get without a third hole in the lower.


The results have been almost boring reliability. I shoot a fairly high round at 3-gun matches every year and AR-15 malfunctions are so rare as to be noteworthy. The AR-15 is a superb design and with modern manufacturing processes as long as you avoid pure junk like Hesse or Blackthorne, you are going to be fine. There are only a handful of companies that manufacture bolts, carriers, and barrels. Continental Machine and Tool (CMT/Stag) is one of the largest.

If you have any capacity for attention to detail whatsoever, it is difficult to assemble an AR-15 that doesn't work properly.







http://youtu.be/WMYTdsc3FUQ

 

[C-grunt]

"An AR that is built using parts from different manufacturers runs the risk of having those parts not wanting to work together properly...." -- C-grunt

Well, sure...there is a risk if you don't choose well. Otherwise, your advice is arrant nonsense. It's the sort of speculation that makes mechanical engineers grind their teeth.

Well-made parts of proper materials machined within spec are going to "work together". Why would they not?!

"But unless you are willing to do the work that quality manufacturers do to design and test a rifle system, a home build will likely not be as good." -- BingoFuelUSN

And why not? It's not like there aren't decades of experience disproving your contention.

"And it will be hard to know how good it is because a single version shot by one user isn't going to provide lot of interesting testing data."

How exactly do you think that data bases are built? Really, sir, this sort of "reasoning" is amateurish at best and harmful at its worst.

We're building ARs...not helicopters.

Did you not read my last paragraph? I said select parts that work together and are quality. I further said in my first sentence that it's entirely possible to build a very reliable AR15.

I have A LOT of experience with the AR platform. I have used them professionally my entire adult life. The original posters question leads me to believe that he is not a guru of the Stoner rifle. Therefor when a novice asks for the most reliable rifle they can get suggesting a complete rifle from companies that are combat proven is what I do. Because to me when someone asks for the most reliable rifle they can get it suggests they are probably looking for a serious use weapon.

 

[GAMEOVER44]

Just buy a colt and be happy, your NOT going to get much better in terms of real-world performance.

 

[IndianaBoy]

Just buy a colt and be happy, your NOT going to get much better in terms of real-world performance.

Respectfully disagree. Colt makes a great rifle if you are looking for a patrol carbine if you are a law enforcement officer.

They don't make a rifle that is ideal for varmint hunting, target shooting, 3-gun competition, NRA High Power..... etc.

They are a one trick pony, and I think many shooters are done a disservice by being told to 'Just buy a colt.' Yes it will probably be reliable. But it probably won't have the external configuration or the shooting characteristics that are available from many other makers whether it be a factory rifle or a home build.

 

[Blade First]

"Did you not read my last paragraph?" -- C-grunt

Is that the paragraph that begins with 'However'? Not only did I read it again, I reread your advice in the next-to-the-last paragraph.

I don't doubt for a second the experience that you provide us...it's the experiences which you haven't had that are the basis of my disagreement.

My sincere thanks to you for your service to our country.

 

[Blade First]

"While that was a kinda brunt, Blade First, that's pretty much what I'm talking about." -- .Scarecrow

Heh...can be blunt from time to time; sometimes slip into curmudgeon-mode.

By the way, I have more stuff inbound from Aero. Their only problem is that they are so busy making and shipping parts that they don't have time to answer the phone.

Have not used any of Faxon Firearms products but have used Aero Precision barrels in three calibers. Top notch, right down to published v. actual specs and QPQ treatments.

Intend to use Faxon and Sionics for parts in the near future...there's always the next experiment to conduct.

 

[C-grunt]

"Did you not read my last paragraph?" -- C-grunt

Is that the paragraph that begins with 'However'? Not only did I read it again, I reread your advice in the next-to-the-last paragraph.

I don't doubt for a second the experience that you provide us...it's the experiences which you haven't had that are the basis of my disagreement.

My sincere thanks to you for your service to our country.

First Id like to point out that I dont count my military service as making me any sort of expert on the rifle. God knows there is a WHOLE BUNCH of crap info being passed around in the military about the rifle. I have learned far more about the AR as a civilian and LEO than I ever did in the Army. I just like to point out that fact since we all dont know each other and I try to show that Im not some guy who bought an AR a year ago and consider myself an expert on it. Way to many of those guys out there. I consider myself a long term student.

I am also a certified armorer through Semper Paratus and am friends with the owner/instructor. He has taught me a lot about the weapon.

I have built/assembled a few ARs for myself and friends and have fixed and troubleshot (troubleshooted??) others that were not working correctly. Ive seen several problems stemming from overgassed barrels and carbine buffers. Ive seen rifle uppers on carbine receiver extensions using light buffers. Ive seen a 10.5 inch "milspec" barrel with a 0.095 gas port. I thought up a few more at the gym but can't remember them right now.

Like I said before any one of those scenarios are probably going to work and be reliable for the average shooter. However take some high stress classes or duty use exercises and they will start to fail.

However if you have some insight to the contrary please add it. Thats not sarcasm in any way. Im always up for a good discussion on the AR with knowledgeable people. Dont worry about being blunt either. I get called very mean names by criminals regularly. I can take it.

 

[C-grunt]

Intend to use Faxon and Sionics for parts in the near future...there's always the next experiment to conduct.

You wont be disappointed with Sionics.

Faxon looks like it has real potential. Their "ask us anything" thread over on M4Carbine was very informative. If you havent seen it go check it out.

 

[.Scarecrow.]

Well C-Grunt, I have seen even well touted AR's jam during tactical carbine classes. Every gun can jam, as I'm sure you know. I still want to go from the evidence that has been placed in front of me, with all due respect.

 

[C-grunt]

Go for it. Just use quality parts and research.

It's true that any gun can malfunction. But when my department switched from Bushmasters (Improperly built) back to Colt the malfunctions went from a few every training session (out of 15 or so shooters) to practically non existent. Biggest problems with the Bushmasters were over gassed barrels and carbine buffers, plus 223 spec chambers popping primers when shooting 5.56.

 

[Blade First]

"First Id like to point out that I dont count my military service as making me any sort of expert on the rifle."

Don't expect that at all...and don't care what your current MOS [still valid nomenclature?] is or what your quals show. It's not really germane. The ability to use a particular piece of machinery implies absolutely no ability to construct or repair same.

If your experience was like mine, even if you qual'd as an 'expert', it didn't make a bit of difference to your drill instructor [or whatever you call that persecutor/tyrant who rousted your ass @ 0430 for a long run before a two-minute "breakfast"] ... real life was, and is still, emphatically real life.

There is a thin line between being a rookie and a troop who has the skills to get it done in dangerous situations.

We may or may not agree on that, but keep in mind that my data base is significantly deeper than yours regarding this particular subject. You've built several ARs. I've built a few more.

Building an AR is more a matter of attention to detail and assurance of quality of parts than it is being a superior mechanic...but you cannot dismiss the latter. If you have that skill, you'll exceed anything the most sophisticated machinery can produce. In some scenarios, that means the difference between failure and success...and if you are the recipient of same, what difference does it make what your job title is?

 

[C-grunt]

"First Id like to point out that I dont count my military service as making me any sort of expert on the rifle."

Don't expect that at all...and don't care what your current MOS [still valid nomenclature?] is or what your quals show. It's not really germane. The ability to use a particular piece of machinery implies absolutely no ability to construct or repair same.

If your experience was like mine, even if you qual'd as an 'expert', it didn't make a bit of difference to your drill instructor [or whatever you call that persecutor/tyrant who rousted your ass @ 0430 for a long run before a two-minute "breakfast"] ... real life was, and is still, emphatically real life.

There is a thin line between being a rookie and a troop who has the skills to get it done in dangerous situations.

We may or may not agree on that, but keep in mind that my data base is significantly deeper than yours regarding this particular subject. You've built several ARs. I've built a few more.

Building an AR is more a matter of attention to detail and assurance of quality of parts than it is being a superior mechanic...but you cannot dismiss the latter. If you have that skill, you'll exceed anything the most sophisticated machinery can produce. In some scenarios, that means the difference between failure and success...and if you are the recipient of same, what difference does it make what your job title is?

That is where we agree. Any monkey can throw together an AR. Knowing what is wrong when it doesnt work is another story.

That is my point. If the OP were asking questions like "H2 buffer vs Vltor A5 system" or "which adjustable gas block for my Daniel Defense Mk18" or any other question that made me feel like he really knew what he was talking about then Id say definitely build it. However I didnt get that impression from the OP's post so I suggested buying a complete.

Also. Scarecrow I am in no way trying to insult or belittle you. If I got the wrong impression of your AR knowledge I apologize. Kind of hard to tell true meaning of what people say on the internet.

 

[.Scarecrow.]

Well you know C-Grunt, I do feel as though you didn't get my knowledge somewhat. The reason I asked such a general question was because I, for a long time, thought that there was something special to building an AR. After watching several AR build videos, it looks like it's mostly just Lego's. I'm quite mechanically inclined and taking anything apart and putting back together is a breeze for me. The biggest thing I learned was the relationship between gas port and buffer weight. Which, what I have heard recommended in terms of buffer weight was to run the heaviest buffer that I can, while still achieving last shot hold open, every time. Those example questions you posted sound like things I might ask, haha. I'm also the type to research the crap out of something before I make a move.

I totally understand your assumption of my overall knowledge, and I don't take any offense.

Hey thanks a lot guys, C-Grunt has already helped me on my Sionics Barrel thread, and there may be a few more before the end, Lol.

Oh and C-Grunt, those Bushy's sounded pretty messed up.

 

[GAMEOVER44]

Respectfully disagree. Colt makes a great rifle if you are looking for a patrol carbine if you are a law enforcement officer.

They don't make a rifle that is ideal for varmint hunting, target shooting, 3-gun competition, NRA High Power..... etc.

They are a one trick pony, and I think many shooters are done a disservice by being told to 'Just buy a colt.' Yes it will probably be reliable. But it probably won't have the external configuration or the shooting characteristics that are available from many other makers whether it be a factory rifle or a home build.

The colt 6940 and 6920 are both competition grade rifles that could be used for target shooting. I dont understand where you came up with that statement. They're also upgradable..

 

[IndianaBoy]

The colt 6940 and 6920 are both competition grade rifles that could be used for target shooting. I dont understand where you came up with that statement. They're also upgradable..

LOL!

Says the guy who apparently doesn't own one yet?

http://www.thehighroad.org/showthread.php?t=774439


Every AR-15 is 'upgradeable', but you are going to replace more than half of that rifle no matter what discipline you want to shoot.

I'm not a Colt hater. They make a reliable rifle. They also ignore a lot of very fundamental refinements that have been embraced by makers like Daniel Defense and BCM. Colt is nothing special in the current market. Their rifles are consistently selling for $300 dollars less than they did a couple years ago because BCM and DD were offering a far better rifle at the same price point.



For competition grade rifles, I don't think I have seen a Colt 6920 at a 3-gun match more than once or twice since 2006. And those were generally in the hands of novices. I don't shoot NRA High-Power but I guarantee you that you are not going to see a Colt 6920 on the 600 yard line.

Yes they are 'accurate enough', generally. And they are reliable. It is more the Indian than the arrow and a great shooter with a stock Colt can beat a schlub with a tricked out JP. But people who don't know any better keep selling this bill of goods that a Colt 6920 is the greatest AR-15 the world has ever seen, and that simply is not true. And a lot of people wind up with a rifle that really isn't great at anything, because they were told what to buy by people who have spent more time regurgitating BS they read online than actually shooting.

The carbine length gas system alone is a reason to choose something other than a Colt if you are really interested in shooting a rifle in an optimal configuration.


For guys who are interested in 'tactical' rifles I would lean towards BCM or DD.

For guys who are shooting recreationally. you can make a good case for anything as simple and inexpensive as an entry level DPMS all the way to something like a JP, Seekins Precision, or if performance at a given price point is you ultimate criteria and this is going to be a game gun and not for something serious like a patrol carbine, a home build is often the most cost effective way to achieve the ideal rifle.