Couldn't find a specific thread on accurizing your own AR as budget allows.

Obviously the best barrel (Kriegers get mentioned a lot) helps, but what else can you do to an upper/lower to squeeze the most out of your platform?

I don't want to BUY an accurized upper. I find lots of enjoyment from tricking out my own rigs, and have done many handguns and bolt rifles over the years.

I already have an M4 for all around shooting, but now I have built an Aero Precision lower and RRA 2 stage LPK to get up and running with something a little more specialized. I have a DPMS lo pro classic bull barrel upper mated to it right now, but have barely started ammo testing. I consider this to be just a starting point.

Any tips, tricks, parts recommendations? What gives the biggest bang for the buck first? I know it becomes a curve of decreasing returns after a point.

Does anyone here cut their own chambers or recrown?

AMMO, AMMO and more MATCH GRADE AMMO!

It's all about a good barrel and good ammo. If you don't want to buy a new barrel, float your barrel, buy match ammo or reload your own.  

There is almost nothing you need to do - or CAN do - to the lower to improve accuracy.  The only really effective lower mod is to "improve your trigger."  That means different things to different people, and it is also dependent on what you want to do with the rifle, but in general, a lighter, smooth and crisp trigger will make your rifle more accurate by reducing the vibration and lateral deflection YOU induce by your pull on the trigger.

If you're after a long range "paper punching" range rifle, go with one of the well known aftermarket triggers, like a Gissele.  If you want the most accuracy from a more tactical rifle, break in your stock trigger, or have Bill Springfield smooth it out and lighten it a bit.  A well broken-in stock trigger will be a whole lot smoother than a new one, but it will still be in the 7-10 pound range.  Bill Springfield (www.triggerwork.net) can both smooth it (VERY well!) and lighten it to 4 pounds or so.

Trigger and ammo is the main things.

Once you push that to its limits, then barrel replacement.

All of my triggers on all my guns are either 2 stage (rifles) or have been reworked (by me) to smooth them out (action job) and lower the pull weight.  I decided to limit myself to no less than a 4.5 lb pull on my M4. With a long range rifle I can see going much lower. I already shoot benchrest with a 1 lb  adjustable 2 stage trigger, but that may be too low with the 5.56 recoil and coud lead to inadvertent bump fire.

Hand loading makes perfect sense. That's all I use on my customized (again by me) 300 WM elk gun. 600 yds is like 200 yds on a stock rifle.

I guess other than a top notch barrel there isn't much to do with and upper. I had hoped that there were bolt or BCG tricks and tips to be had but I guess not.

No one modifies their own chambers either? I have looked at the  Wylde chamber and also wouldn't mind going straight 223 since I won't be shooting military ammo in it. Hmm...I guess some of the other cal's may be worth checking into.

Thanks for the info guys.

I would certainly not worry about the chamber until I'd gone through all the other options.  A good trigger and good ammo are the first things to look at.  I'd work on getting a hand load worked up that is as accurate as possible before considering anything else.

As for the BCG and bolt, there is almost nothing that they do that could be tweaked.  I guess in a bolt gun you could be concerned about how much static pressure the bolt face applies to the case head or something else like that, but in an AR, the bolt either is "in spec" or it isn't, and it would be rather difficult to intentionally make a bolt do something different.  The carrier?  It just keeps the bolt centered and moves it back and forth.  (Technically you could concern yourself with the gas rings, whether the carrier is chrome (or something else) lined, but that would be more of an issue with function, not accuracy.)

If you want your rifle to get better accuracy results......look at ammo or a better barrel.

If you want the shooter to be a more accurate shot.....look at a nice trigger first.

I remember seeing a kit for truing up a AR upper receiver . You would think having the face square with the barrel extension and having a good fit between the barrel / upper would help.

You can get it from Brownells, rather inexpensively too-$35.  It can't hurt to check the face being true-and sometimes either finish machining or anodizing gets it "not quite right."

Free float tube, handloads, barrel, and trigger. in that order, assuming you have decent optics will get you a pretty damn good shooting rifle.  From there you can go into getting special BCGs, lapping stuff, adjustable gizmos etc..

barrel, Ammo, Trigger, free float, good optic and mount, is about 98% of it.  tweaking out that last 2% gets expensive

Well, that sounds like a concensus to me, as far as it goes.

Funny, no one mentioned the fit between upper and lower, or in the LPK. Slop is the enemy of accuracy in every gun I've ever owned incuding semi autos.. With a 2 piece gun it seems like a loose fit would mean that the hammer never falls on the firing pin consistenly, or that BCG tolerances could push a round into the chamber differently each time. Even the extractor fit can affect how the case is held as it goes into battery. Hammer weight, hammer retun spring weight, firing pin material, torque specs are all things I've had to take into consideration with other guns. I know they aren't AR's but once you go past the SHTF syndorme (that's why we all have our go to M4) and get to a paper puncher these things have to matter.



No offense, but that makes no sense to me at all. If I am going to start by spec'ing  out a barrel from Krieger or Wilson or whoever. I think I would want the most accurate chamber on the market. I am new to .AR's but I see dozens of caliber options available (some just for throwing lead and some for accuracy) and that all comes down to different chambers for different results.

This mythical "Accurate" rifle that we have been discussing is a long term project, not the 90 minute build that my M4 was. I appreciate the starting points, and they make good sense, but am still looking for even the little "tweaks" that can make a difference downrange.  

Has anyone experimented with any of this?

Get a high quality SS barrel. (1 in 8 twist preferably)
Get a nice trigger.
True the face of the receiver.(optional but recommended)
Get a Mil-Spec BCG
Get a free floating handguard
Match Ammo
And do not skimp on the glass or mounts.

Everything else is based on your personal taste.

Basically, accurizing an AR is selecting the right parts. Thats it.

I've read about the crowns being re-done.

Unless a 16" or longer AR barrel shoots sub-1 MOA groups, or even better, how is one to know if the barrel they bought has as good of a crown as it could have?  (that is considering that a very stable platform, high magnification scope and a good trigger pull are already being used)

I may have the crown on my mid-level barrels re-done to see what it does to increase accuracy - of course I was already hand-loading for accuracy.

I didn't say "don't consider what chamber will work best for your intended purpose."  I said not to worry about it until I'd gone through the other options for accurizing first.  Putting a fabulous barrel with "the perfect chamber" on an upper whose face isn't true to the bore axis is dumb.  So is buying a dead-stock trigger and expecting to shoot sub-MOA the first time out with that trigger.  But spec the rest of the rifle first, because most of the rest of it will be less expensive combined than the really great barrel you want.

After that, think HARD about a SAAMI .223 Remington chamber-particularly the leade and freebore that's part of that spec.  The SAAMI spec was intended for bolt guns, not semi-autos, and I think that makes a HUGE difference.  Magazine length limitations will almost certainly keep you from being able to do many of the ammo accurizing steps you can do with a bolt gun, such as seating for a specific distance between the bullet's ogive and the beginning of the rifling.  On the other hand, with a Wylde chamber, you can do a lot of stuff you can't with a SAAMI chamber, like load for higher velocities (and pressures) with heavier bullets safely, taking advantage of the longer freebore and more gradual leade in the Wylde chamber without any of the perceived down sides of the NATO chamber.

Finally, my advice about "worry about the chamber last" goes double for people who want to make an existing rifle more accurate.  The barrel is the most expensive single part of a stock AR; deciding you can get better accuracy by changing barrels before addressing your ammo, your trigger, your ergonomics, and your barrel to upper fit doesn't make sense; you could find out that you already have a pretty darn good barrel but you were limited by having it installed in an off-true upper and using a creepy and heavy trigger.

I agree with GHPorter.  Your barrel might be a tack driver without free floating it and worrying about slop in your upper and lower and getting a new barrel and whatever.  You get a good mount with some serviceable optics.  You get some good ammo, then you see what it can do.  I've gotten some pretty good groups with single stage triggers, non free floated, run of the mill barrels.  I think finding the ammo your barrel likes is actually the most important.  If you find that your barrel isn't doing it for you, it's either you, or you need to move on.  But most of the time, people that ask these questions, just want an excuse to feel like they need all kinds of gadgets and upgrades to shoot well.  Well, go ahead and get them if you want, but they're not necessarily a requirement for an AR to shoot real good.  Plus, what is your need and what is good shooting?  If you want consistent sub MOA, well, you probably will need more gear.  If you want to keep it MOA or 2 consistently, you may just need the right load.

My 2 cents.

It's really that simple. AR's aren't like Bolt guns and 1911s where you can sit in a machine shop and tweak them all day long. Of course you could do that with an AR but it wouldn't get you a whole lot.

Barrel, ammo, and trigger are really key.

I like JP yellow springs on my RRA 2stg. You can polish the trigger pins and inside surface of the trigger where it contacts the pins. Very careful trigger polishing help(I send mine to Bill Springfield for this). Truing up the receiver face on a std A4 receiver won't help you much if it all. Starting with a match receiver like a billet Rainier may help a bit since it is trued up in every way. You must free float the barrel, preferably a stainless match barrel.