Inside our Shooters’ Forum, one member recently asked: “What makes an AR accurate? What parts upon an AR can really affect accuracy – for example free-floating handguards, barrels, bolts, bolt carriers?” He wanted a truthful, well-informed answer, not only sales pitches. Robert Whitley posted a very comprehensive response to this, based on his experience building and testing dozens of cheap AR15 uppers for sale. Robert runs AR-X Enterprises, which produces match-grade uppers for High Power competitors, tactical shooters, and varminters.
There are tons of things that you can do to a AR to boost consistent accuracy, and I make use of the words “consistent accuracy” because consistency is an element of it (i.e. plenty of guns will provide several great 5-shot groups, but won’t do a good 10- or 20-shot groups, and several guns will shoot great some day and not so great on others).
Allow me to share 14 key things we think are essential to accuracy.
1. Great Barrel: You’ll want a premium match-grade barrel, well-machined with a decent crown plus a match-type chambering, true towards the bore and well cut. The extension threads also needs to be cut true for the bore, with everything else true and also in proper alignment.
2. Rigid Upper: A rigid, heavy-walled upper receiver aids accuracy. The typical AR upper receiver was created for the lightweight carry rifle and they stripped every one of the metal they can off it making it light to handle (that is advantageous to the military). The net result are upper receivers that are so thin you may flex them your bare hands. These flexible uppers are “strong enough” for general use, but they are not well suited for accuracy. Accuracy improves using a more rigid upper receiver.
3. True Receiver Face: We’ve learned that truing the receiver face is valuable. Some may argue this aspect but it is always advisable to keep everything associated with the barrel and also the bore in complete alignment with all the bore (i.e. barrel extension, bolt, upper receiver, carrier, etc.).
4. Barrel Extension: You need to Loctite or glue the barrel extension in to the upper receiver. This holds it into position completely front to back in the upper receiver. Otherwise when there is any play (and there typically is) it simply hangs on the face of the upper receiver completely influenced by the face of your upper receiver because the sole method to obtain support for the barrel as opposed to being made more a fundamental part of the upper receiver because they are glued-in.
AR-X AR15 Upper5. Gas Block: You need a gas block that will not impose pointed stress in the barrel. Clamp-on types that grab entirely throughout the barrel are great. The blocks that happen to be pinned on with tapered pins that wedge versus the barrel or even the slip on sort of block with set screws that push up from underneath (or right on the barrel) can deform the bore inside the barrel and might wreck the precision of an otherwise great barrel.
6. Free-Float Handguard: A rigid, free-float handguard (and i also emphasize the saying rigid) really makes a difference. There are lots of forms of free-float handguards plus a free-float handguard is, in as well as itself, a massive improvement over a non-free-float set up, but best can be a rigid set-up. A few of the ones on the market are small diameter, thin and/or flexible and if you are shooting off almost any rest, bipod, front bag, etc., a rigid fore-end is better since ARs would like to jump, bounce and twist whenever you let a try go, since the carrier starts to begin its cycle ahead of the bullet exits the bore.
7. Barrel Contour: You desire some meat in the barrel. In between the upper receiver along with the gas block don’t go real thin using a barrel (we love 1? diameter if it’s workable weight-wise). Whenever you touch off a round and also the bullet passes the gas port, the gas system immediately starts pressuring on top of a gas impulse that provides vibrations and stress on the barrel, especially between your gas block back to the receiver. A heavier barrel here dampens that. Staying a little heavier with barrel contour with the gas block area and over to the muzzle is perfect for the identical reasons. ARs use a lot taking place once you touch off a round and also the gas system pressures up along with the carrier starts moving (all ahead of the bullet exits the bore) so the more the situation is made heavier and rigid to counteract that the better – within reason (I’m not advocating a 12-lb barrel).
8. Gas Tube Routing Clearance: You will want gas tube that runs freely with the barrel nut, with the front of the upper receiver, and thru the gas key in the carrier. Make sure the gas tube is not really impinged by some of them, so that it does not load the carrier inside a stressed orientation. You don’t want the gas tube bound up in order that once the gas tube pressures up it immediately desires to transmit more force and impulse for the barrel than would normally occur. We sometimes spend a 63dexjpky of your time moving the gas block with gas tube off and on new build uppers and tweaking gas tubes to get proper clearance and alignment. Most gas tubes do need a little “tweaking” to acquire them right – factory tubes may work OK nevertheless they typically tend not to function optimally without hand-fitting.
9. Gas Port Tuning: You need to avoid over-porting the gas port. Being over-gassed makes the gas system pressure up earlier and much more aggressively. This leads to more impulse, and increases forces and vibration affecting the most notable end as well as the barrel. Tune the gas port to give the level of pressure necessary to function properly and adequately but forget about.
10. Front/Back Bolt Play: If accuracy is definitely the game, don’t leave a great deal of front/back bolt play (ensure that it stays .003? but a maximum of .005?). We’ve seen factory rifles run .012? to .015? play, that is OK if you have to leave room for dirt and grime inside a military application. However, that amount of play is not really ideal for a higher-accuracy AR build. A lot of front/back bolt play allows rounds being hammered to the chamber and re-formed in the non-consistent way, since they are loaded to the chamber.
11. Component Quality: Use good parts from the reputable source and stay wary of “gun show specials”. All the parts will not be the identical. Some are excellent, some usually are not so excellent, plus some aftermarket parts are simply bad. Don’t hesitate to utilize mil-spec-type carriers; generally they can be excellent for an accuracy build. Also, keep in mind that because a carrier says “National Match” or something else into it does not always mean it’s any better. Be suspicious of chrome-plated parts as being the chrome plating can change the various components dimensionally and will also allow it to be difficult to do hand-fitting for fit and performance.
12. Upper to reduce Fit: A good upper/lower fit helps. For fast and dirty fit enhancement, an Accu-Wedge within the rear helps a whole lot. The supreme solution is to bed the upper to a specific lower in order that the upper and lower, when together, are definitely more like one integral unit. For your upper receivers we produce, we try to obtain the specs as close while we can, but still fit the many lowers in the market place.
13. Muzzle Attachments: Don’t screw within the muzzle (literally). Leave just as much metal on the barrel with the muzzle as possible. People prefer to thread the muzzle for any flash hider, suppressor, muzzle brake, as well as other attachment, but if you truly want accuracy, leave as much metal as you can there. And, when you have a thing that screws on, set it up up in order that it may be placed on and have it stay there without putting a lot of torque and stress upon it right where bullet exits the bore. If you are planning to thread the conclusion of the barrel, allow it to be concentric with all the bore and be sure what you screw on the website is really as well. For many muzzle attachments, also be sure that the holes whereby the bullet passes through are dead true towards the bore. Many aftermarket screw-on situations are not so good doing this. Everything that vents gas should vent symmetrically (i.e. whether it vents left, it should vent equally right, and likewise, if this vents up, it should vent down equally). Uneven venting of gas can wreck accuracy.
14. Quality Ammunition: Ammo is really a whole story on its own, but loads which can be too hot typically shoot poorly in best AR15 manufacturer. If you want accuracy from an AR-15, avoid overly hot loads. Shown listed here are test groups shot with four (4) different uppers, all with moderate loads. These four uppers all pretty much had exactly the same features and things performed to them as explained on this page, and so they all shot great.