Three biggest things:
Good quality barrel
Good consistant ammo that weapon likes
Learn to shoot

It's not hard so long as you concentrate on these components:

Barrel
Trigger
Optics
Ammo

I can see the potential value of a rigid receiver with a trued face, but I'm not sure where you'd find such a thing.

where does one get a heavy walled upper receiver?

Yeah that article is talking about shooting tiny groups, not just 5/8-3/4 moa which is fairly  easy with a great barrel bolted to an upper receiver and a great load with a good bullet.

That guy really goes all out, personally I have no use for that type of accuracy. Shooting long range where I can have 50-100" of wind drift and no flags, the difference between a 1/4moa and 1 moa rifle means 1 more hit out of 100 shots.
Get better hit improvement by dropping MV SD a few FPS.

upgrading from a forged upper to a vltor cnc upper made my larue barrel shoot more consistant groups 

In the linked article, points 2, 4, 5, 9, 10, and 12 are nothing more than the author's hunches (with which many good shooters disagree) that he's passing off as facts. Working off trial and error and hunches is fine, as long as you recognize what you're doing. The problems start when people try to pass off a hunch as a fact.

As for #4, using any Loctite product for structural support in a high heat area is a highly questionable proposition.

Once you start getting into pushing the accuracy limits of any rifle, trial and error and hunches take over for objective tests and proof. This is true mainly because 1) there are so many variables in play when you're talking about going from 3/4 moa to .5 moa or below that it's nearly impossible to isolate and test for any one variable; and 2) doing #1 is so expensive and time consuming, proceeding on a trial and error basis makes sense. The upside to trial and error is you eventually get smaller groups. The downside is you're not 100% sure of why the groups shrunk.

An example is pillar bedding bolt action rifles. Ask somebody to explain what it does to improve accuracy with a free-floated barrel. Then ask what they've done to test whether it works. Pillar bedding makes sense for some rifles in some stocks. But, in my opinion, it's pointless for most modern rifles and stocks. Sure, you can come up with reasons why it might help, but I've yet to see anyone objectively test them to establish that it does help absent a specific problem with a stock. I have pillar bedded a rifle, and I've researched the subject extensively. Evidence of pillar bedding's general usefulness for a free-floated rifle is purely anecdotal. Yet, doing it all the time remains conventional wisdom in the bolt gun world.

Another good one is bore cleaning. Bench rest shooters usually clean very frequently. Often every 20 rounds or so. Most other kinds of precision shooters have moved away from frequent cleanings and deep clean every 200-300 rounds. They can't both be right. Yet, you won't find any objective testing of either theory.

I'm also calling bullshit on that target. Somebody that's serious about group size doesn't use shoot 'n see targets and measure by sticking the calipers somewhere near the middle of the holes. Real accuracy nuts are way too precise for that. I also don't see how that could possibly be eight 6mm holes on a shoot 'n see. It might be four.

If you want to build an accurate AR, here's my opinion about the order of importance: 1) barrel, 2) ammo, 3) optic mount, 4) trigger, 5) free floating the barrel, 6) optic, 7) stock, and 8) bolt. You're not getting anywhere if 1-3 suck. You're not getting very far without adding 4 and 5. 6-8 fine tune things.

Of course, you can't use defective or out of spec components, but that should go without saying.

Robert Whitley sells 6mm wildcats based on the 6.5 Grendel case. He is a very knowledgeable and well regarded gunsmith, experimenter, businessman, lawyer. Buy any of his products and you won't be disappointed. www.6mmAR.com is his website.

He is a contributor to www.accurateshooter.com probably the best website today concentrating mainly on long range and extreme rifle accuracy. You can trust anything he says regarding building AR-15 rifles.

I believe Mega Machine sells heavy upper receivers with side charging handle cuts. DPMS has one as well, so does Sun Devil Mfg. Several other companies may be sourced that I can't recall at the moment. Excellent accuracy can be obtained using standard G.I. uppers, but heavier upper receivers flex less when heavy barrels are being used.  

Anyone interested in learning more about Mr. Whitley should visit his website.

This was an old post...much of it looked like over kill to me.. Or maybe I don't have the place to shoot or the skills to take advantage of anything more that Barrel, trigger and free float.

Hellbenders guide to the AR...

Well benchrest rifles are built a certain way, they get tiny groups, so the closer you can get an AR to a benchrest rifle..?...... being real simple about it.

Good heavy barrels, stiff actions, concetric chambers, bolts and bores, apply that to an AR, seems logical.

To each his own, but that goes way beyond what I am looking for out of an AR.

I don't think questioning the shooter because he uses shoot n see targets is really valid criticism.

If you're consistently shooting .75moa and you want to shoot a half moa or better, I could see going down the rabbit hole and trying some of these suggestions out.

By and large FOR ME, that level of accuracy is not something I need out of a gas gun.

Other than that, fpni

I would like to also draw attention to the point that he made in the first paragraph about a 5 shot group vs a 10-20 shot group.
Did this guy teach Molon the shooting gospel?

Most folks  who shoot guns know and understand that 10-20 shot groups tell you more than 5 shot groups do.

#thatsthejoke

This. Multi-tools usually suck at most things.

Also, I've seen people hold 1moa with crappy guns and decent ammo. The shooter matters more than anything in my opinion. Anyone can use a screwdriver, but not everyone can use it properly.

And one more tidbit to add, i don't like the use of accuracy. Accuracy, precision, and consistency are different things, different aspects of firearms, and should not be grouped in one terminology.

Anyways, good thread.

I questioned the shooter because 1) it's unusual to see someone serious about precision shooting use shoot 'n sees, probably because there's no grease ring to measure from and they usually own optics that render them pointless; 2) serious precision guys usually don't lay their calipers in the middle of the holes to measure; and 3) it looks like four holes not eight. All of those things make me doubt that is a 100 yard, 8 shot group.

Also, that's the author's customer's target, not the author's. I think it's bullshit. The shooting world is and has always been full of it.

Are you suggesting that an AR15 cannot be made to put multiple shots through the same hole? Because I would definitely disagree with that.
As was stated above, the article wasn't about shooting groups that are "accurate enough". The article was about how you can shoot serious groups. Not half inch. Better. When you're talking about that level of accuracy, you can put 8 shots into a group that size. That's what the author is demonstrating.

I am suggesting exactly what I said. Nothing more, nothing less. I do not believe that target is an eight shot, 100 yard group. I do not know why you feel the need to put words in my mouth.

I'm quite aware that ARs can be accurate. Here is a target I shot yesterday with one I built. This was 100 yard testing with American Eagle 50 grain varmint tips following a thorough cleaning. I think you can see where it settled in. Those faint grid lines are 1/2".

While I'm sure a lot of these do make slight gains on some rifles, in general I would be willing to bet that dry firing consistently would show far more gains.  You would have to be a good enough shooter first to benefit from a lot of those; I for one am not there yet

Ugh. These guys and there 10-20 round groups. All they are doing is introducing a chance for outside influences.  They'll deny that and try to sound official while doing it but this is coming from back yard testers who know little to nothing about actually scientific testing. And even if they do I've seen nothing but them testing in their spare time. Not in real controlled environments.

Five, maybe seven is plenty.

And what people need to realize is there is almost no "real" scientific testing on guns, ammo, accuracy, precision, eat cetera.

I'm talking about true scientific method. What we have is back yard testers, who in some cases do a great job, but thats all they are. No real scientific conclusions can be drawn from what they do.

They fail in so many ways if you really hold them to a true scientific standard. Shit, half the time they don't even use a control. Or think they do but don't have a clue what a real control is. Not to mention how much money they'd have to spend to get the proper amount of testing done.

Let me be clear, they can bring some valuable information to the table. But scientific?  Properly done?  No. my problem is the attitude some of them show. You're back yard testers who can deliver valuable information. Not scientific information. There is a difference.

You seem really smart thanks for your contribution

Houston Warehouse.
Google it.

Thanks for that. This was a good read. Gave me some stuff to tinker with in reloading.