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December 8th, 2021

The Tack-Driving AR — Secrets to AR Platform Accuracy

AR-X AR15 Upper

One Shooters’ Forum member asked: “What makes an AR accurate? What parts on an AR can really affect accuracy — such as free-floating handguards, barrels, bolts, bolt carriers?” He wanted an honest, well-informed answer, not just sales pitches. Robert Whitley posted a very detailed answer to this question, based on his experience building/testing scores of AR-platform rifles. Robert runs AR-X Enterprises, which produces match-grade uppers for High Power competitors, tactical shooters, and varminters.

AR-X AR15 Upper

Building an Accurate AR — What is Most Important

by Robert Whitley
There are a lot of things that can be done to an AR to enhance consistent accuracy, and I use the words “consistent accuracy” because consistency is a part of it (i.e. plenty of guns will give a couple great 5-shot groups, but won’t do a very good 10- or 20-shot groups, and some guns will shoot great one day and not so good on others).

Here are 14 key things we think are important to accuracy.

1. Great Barrel: You’ll want a premium match-grade barrel, well-machined with a good crown and a match-type chambering, true to the bore and well cut. The extension threads must also be cut true to the bore, with everything true and in proper alignment.

2. Rigid Upper: A rigid, heavy-walled upper receiver aids accuracy. The typical AR upper receiver was made for a lightweight carry rifle and they stripped all the metal they could off it to make it light to carry (which is advantageous for the military). The net result are upper receivers that are so thin you can flex them with your bare hands. These flexible uppers are “strong enough” for general use, but they are not ideal for accuracy. Accuracy improves with a more rigid upper receiver.

3. True Receiver Face: We’ve found that truing the receiver face is valuable. Some may argue this point but it is always best to keep everything related to the barrel and the bore in complete alignment with the bore (i.e. barrel extension, bolt, upper receiver, carrier, etc.).

4. Barrel Extension: You should Loctite or glue the barrel extension into the upper receiver. This holds it in place all the way front to back in the upper receiver. Otherwise if there is any play (and there typically is) it just hangs on the face of the upper receiver completely dependent on the face of the upper receiver as the sole source of support for the barrel as opposed to being made more an integral part of the upper receiver by being glued-in.

AR-X AR15 Upper5. Gas Block: You want a gas block that does not impose pointed stress on the barrel. Clamp-on types that grab all the way around the barrel are excellent. The blocks that are pinned on with tapered pins that wedge against the barrel or the slip on type of block with set screws that push up from underneath (or directly on the barrel) can deform the bore inside of the barrel and can wreck the accuracy of an otherwise great barrel.

6. Free-Float Handguard: A rigid, free-float handguard (and I emphasize the word rigid) really makes a difference. There are many types of free-float handguards and a free-float handguard is, in and of itself, a huge improvement over a non-free-float set up, but best is a rigid set-up. Some of the ones on the market are small diameter, thin and/or flexible and if you are shooting off any type of rest, bipod, front bag, etc., a rigid fore-end is best since ARs want to jump, bounce and twist when you let a shot go, as the carrier starts to begin its cycle before the bullet exits the bore.

Robert Whitley AR Accurate accuracy aR15 barrel trigger MSR gunsmithing

7. Barrel Contour: You want some meat on the barrel. Between the upper receiver and the gas block don’t go real thin with a barrel (we like 1″ diameter if it’s workable weight-wise). When you touch off a round and the bullet passes the gas port, the gas system immediately starts pressuring up with a gas impulse that provides vibrations and stress on the barrel, especially between the gas block back to the receiver. A heavier barrel here dampens that. Staying a little heavier with barrel contour through the gas block area and out to the muzzle is good for the same reasons. ARs have a lot going on when you touch off a round and the gas system pressures up and the carrier starts moving (all before the bullet exits the bore) so the more things are 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 want a gas tube that runs freely through the barrel nut, through the front of the upper receiver, and through the gas key in the carrier. Ensure the gas tube is not impinged by any of them, so that it does not load the carrier in a stressed orientation. You don’t want the gas tube bound up so that when the gas tube pressures up it immediately wants to transmit more force and impulse to the barrel than would normally occur. We sometimes spend a lot of time moving the gas block with gas tube on and off new build uppers and tweaking gas tubes to get proper clearance and alignment. Most gas tubes do need a little “tweaking” to get them right — factory tubes may work OK but they typically do not function optimally without hand-fitting.

9. Gas Port Tuning: You want to avoid over-porting the gas port. Being over-gassed makes the gas system pressure up earlier and more aggressively. This causes more impulse, and increases forces and vibration affecting the top end and the barrel. Tune the gas port to give the amount of pressure needed to function properly and adequately but no more.

10. Front/Back Bolt Play: If accuracy is the game, don’t leave a lot of front/back bolt play (keep it .003″ but no more than .005″). We’ve seen factory rifles run .012″ to .015″ play, which is OK if you need to leave room for dirt and grime in a military application. However, that amount of play is not ideal for a high-accuracy AR build. A lot of front/back bolt play allows rounds to be hammered into the chamber and actually re-formed in a non-consistent way, as they are loaded into the chamber.

11. Component Quality: Use good parts from a reputable source and be wary of “gun show specials”. All parts are NOT the same. Some are good, some are not so good, and some aftermarket parts are simply bad. Don’t be afraid to use mil-spec-type carriers; by and large they are excellent for an accuracy build. Also, remember that just because a carrier says “National Match” or something else on it does not necessarily mean it’s any better. Be wary of chrome-plated parts as the chrome plating can change the parts dimensionally and can also make it hard to do hand-fitting for fit and function.

AR-X AR15 Upper

12. Upper to Lower Fit: A good upper/lower fit is helpful. For quick and dirty fit enhancement, an Accu-Wedge in the rear helps a lot. The ultimate solution is to bed the upper to a specific lower so that the upper and lower, when together, are more like one integral unit. For the upper receivers we produce, we try to get the specs as close as we can, but still fit the various lowers in the market place.

13. Muzzle Attachments: Don’t screw up the muzzle (literally). Leave as much metal on the barrel at the muzzle as you can. People like to thread the muzzle for a flash hider, suppressor, muzzle brake, or some other attachment, but if you really want accuracy, leave as much metal as you can there. And, if you have something that screws on, set it up so that it can be put on and have it stay there without putting a lot of torque and stress on it right where the bullet exits the bore. If you are going to thread the end of the barrel, make it concentric with the bore and make sure what you screw on there is as well. For all muzzle attachments, also ensure that the holes through which the bullet passes through are dead true to the bore. Many aftermarket screw-on things are not so good that way. Anything that vents gas should vent symmetrically (i.e. if it vents left, it should vent equally right, and likewise, if it vents up, it should vent down equally). Uneven venting of gas can wreck accuracy.

14. Quality Ammunition: Ammo is a whole story by itself, but loads that are too hot typically shoot poorly in an AR-15. If you want accuracy out of an AR-15, avoid overly hot loads. Shown below are test groups shot with four (4) different uppers, all with moderate loads. These four uppers all pretty much had the same features and things done to them as explained in this article, and they all shot great.

AR-X AR15 Upper

Robert Whitley
www.6mmAR.com

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December 8th, 2021

ATF Will Offer New eForms System for NFA Transfers

ATF BATFE eform suppressor silencer nfa transfer application form 1 form 4

This report comes from the American Suppressor Association (ASA).
The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) has announced the imminent launch of a new electronic system for NFA transfers. Known as the eForms system, this overdue modernization will allow consumers to submit both ATF Forms 1 and 4 electronically, hopefully resulting in a significant decrease in transfer times when compared to traditional paper Forms. This should speed up acquisition of firearm suppressors, since these require a Form 4.

According to ATF, the transition to the new system will occur sometime after December 15th, but before Christmas. The new eForms system will handle all existing NFA transfer forms, including the ATF Form 4, which is used for transfers of suppressors.

What is the NFA?
The National Firearms Act of 1934 (NFA) requires the Federal registration of fully-automatic firearms, of short-barreled rifles and shotguns, of rifles over .50 caliber, and of firearms sound suppressors (termed “silencers” under the NFA).

Do NOT Withdraw an Existing Form 4 Submission
If you recently submitted an NFA application, keep it in the queue. The ASA cannot stress this enough. Withdrawing your Form 4 and re-submitting electronically will take longer than allowing your Form 4 to make its way through the approval process. Withdrawing and re-submitting electronically will add months to your overall application process.

That’s because ATF isn’t going to dig through the tens of thousands of forms being processed to find your application. They’re going to wait until your Form 4 reaches an NFA examiner’s desk – the exact point at which it would normally be approved – to process your withdrawal. Instead of approving it though, they will acknowledge your withdrawal and release your serial number. You will not be able to re-submit an eForm 4 with the same serial number until ATF acknowledges your withdrawal and puts it back into your dealers’ inventory.

While traditional paper-based applications will remain a viable option, ASA recommends that suppressor buyers submit new NFA applications electronically. That’s because, if the new eForms system works as promised, it will increase efficiencies by reducing form submission and payment processing times, eliminating weeks of delays in data processing, and all but eradicating data entry errors.

The ASA plans to provide updated information about eForms as soon the ATF officially launches the new program for submitting ATF Forms 1 and 4 electronically. In the meantime, stay tuned by following the American Suppressor Association on Instagram, Facebook, and YouTube.

Once the transition to the new eForms system begins, ATF estimates that the transition will take between two to four days to complete, at which point the new eForms system will go live. ATF has indicated that it will notify the industry 24 to 48 hours prior to the transition, and the ASA will post information as soon as it receives this notifice.

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December 8th, 2021

Three Generations Shoot Together — Grandfather, Father, & Son

father son grandfather young boy benchrest 6mmBR Cooper Montana varminter

We saw a heart-warming post on the Benchrest Shooting and Gunsmithing Facebook Group. Proud father Robb W. explained how three generations of his family — father, son, and grandfather — all recently attended a rifle match together. That’s terrific — three generations on the firing line. But to make things even more special, this was the 10-year-old boy’s very first match. The young man shot a 240-5X. Father Robb was delighted with his son’s performance: “Proud Dad day for sure!”.

father son grandfather young boy benchrest 6mmBR Cooper Montana varminter
We are glad to see the young man uses quality eye and ear protection. Good habit to start.

The rifle used by the young fellow is a Cooper Montana Varminter, chambered in 6mmBR Norma. That happens to be the same cartridge that inspired this Editor to start this website. Before we became AccurateShooter.com, our original site was called 6mmbr.com. You can still find great content on that site, including 100 in-depth Gun of the Week features. 6mmBR.com was launched 17 years ago.

father son grandfather young boy benchrest 6mmBR Cooper Montana varminter

One facebook poster noted: “Keep him shooting. I can tell you from experience, he will be the best shooting partner you will ever have.”

Another reader wrote wisely: “Good for him — Remember that he is the future.”

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