In our Shooters’ Forum, one member recently 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 comprehensive answer to this question, based on his experience building and testing dozens of AR-platform rifles. Robert runs AR-X Enterprises, which produces match-grade uppers for High Power competitors, tactical shooters, and varminters.
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.
5. 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.
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.
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.
Kevin Muramatsu’s black rifle book, the Gun Digest Guide to Customizing Your AR-15, is a great resource for fans of AR-platform rifles. All the AR options you can imagine are covered: suppressors, premium barrels, adjustable stocks, free-float handguards, ergonomic grips, buffer systems, tactical lights and much more. Those planning an AR rifle build will find application-specific suggestions for 3-Gun, Service Rifle, High Power (Space Gun), Hunting, and Self-Defense use.
Firearms expert Muramatsu offers advice on choosing the right stock/barrel/optics configuration for your particular game. He also discusses the wide variety of options for slings, grips, magazines and other accessories. With over 520 photos, the book includes a large photo gallery of customized ARs, and includes bonus coverage of the FAL and other “tactical” firearms. The Gun Digest Guide to Customizing Your AR-15 is available from Amazon.com for $20.13, and a Kindle eBook version is offered for $14.99. The book is also sold by Barnes & Noble, and most other major booksellers.
Share the post "Definitive Book for AR-Platform Gear-A-Holics"
Democratic Presidential candidate Beto (Robert) O’Rourke famously declared “Hell Yes” he is coming to take your guns, starting with AR-15s. In response to that threat, Palmetto State Armory is producing the limited edition PSA “No Beto” AR-15 Stripped Lower Receiver. This precision-made forged aluminum lower can be pre-ordered for just $49.99. On this AR-15 lower, the Fire Selector reads “Hell Yes” (Safe), “Hell No” (Fire), “Snake Bite” (Full-Auto).
All net proceeds from the sale of this receiver will be donated to the nonprofit South Carolina Second Amendment Defense Fund. NOTE: This is a Pre-Order item. Due to unprecedented demand related to the recent political events, please expect lowers to start shipping within 8-9 weeks of order placement.
Palmetto State Armory’s limited-edition “No Beto” AR-15 lower will only be available once and is a limited edition offering. The “No Beto” AR-15 lower is one of the industry’s finest forged, MIL-SPEC lowers. These quality, MILSPEC-designed forged lowers are made with 7075-T6 Aluminum. The Palmetto State Armory “No Beto” AR-15 Lower will accommodate all AR-15 platform builds and is marked “NOBETO-15 MULTI”. The finish is MIL-A-8625, Type III, Class 2 black.
Posting on the 6.5 Creedmoor Group Facebook Page, Russel T. complained that his AR magazine doesn’t like to feed that last few rounds. Russell asked: “Full magazine, no problem cycling. But with five (5) or less in the magazine… this happens. What can cause this?”
It sure looks like he could use a new magazine spring, but there may be buffer-related problems as well. Or maybe a gas system issue. What’s your call? Here are some responses posted by Facebook folks:
“Weak mag spring.” — Josh N.
“Weak mag spring or too heavy of a buffer spring.” — Justin G.
“Try a different mag, if it still jams it’s probably a gas problem, if not chuck the bad mag.” — Otto G.
“Weak mag spring or literally anything that would cause the Bolt Carrier Group to short cycle.” — Reggie W.
“I’ve had the same issue with my 300 BLK when my buffer tube came apart. It would still cycle cheap rounds fine but [not] the Hornadys. Took it apart and found the buffer tube was in pieces.” — Hunter R.
“Could be a weak mag spring or buffer spring, both at the same time.” — John S.
“As mentioned it could be a list of things. However, bolt velocity is too fast/hard and the usual (but not always) culprit is over-gassing.” — Bill F.
“Short cycle — clean and LUBRICATE the weapon.” — Mark H.
“Look to see where the brass is ejecting. That will tell if it’s an over or under gas issue. If that’s ok then look at the mag spring. See Diagram” — Teddy G.
“Weak magazine spring, I tossed four brand new ‘bargain mags’ [due to] that very problem.” — John V.E.
“May not be a weak spring or bad mag. Check out a Tubb Precision flatware spring. I swapped mine in a new rifle and solved the problem of short stroking and double feeds.” — Anthony T.
“It might be the follower as well, some designs will dip in the front/rear as rounds are expended. It’s the reason why we didn’t use some service mags with the green followers.” — Chris J.
“Weak spring… time for a new magazine…or add a 5-round block and make it a 25-round magazine. But I’m positive it’s a weak spring, which means it’s just a matter of time for failure.” — Steve M.
“Without the weapon in hand I would hate to guess….
Start with the simple stuff and go from there. Trying to diagnose a problem from a photo is just like when your wife or girlfriend tells you the car won’t start. LOL.” — Mark T.
Share the post "AR Feed Failure — What Is Your Diagnosis?"
With this insanely good deal from Palmetto State Armory, you can get a pistol AND half an AR rifle for just $379.99 with FREE shipping. The deal is for a PSA AR-15 complete lower with Magpul stock PLUS a M&P Shield compact 9mm Pistol. This is an incredible deal. As Ammoland.com notes: “Compare that price [for pistol plus AR lower] to $430.00 for just the S&W M&P Shield 9mm Handgun elsewhere online.”
Smith & Wesson’s M&P Shield is a concealable, striker-fired polymer pistol with 3.1″ barrel. Overall legnth is 6.1 inches and unloaded weight is just 19 ounces. The Double-action-only (DAO) trigger break consistently at about 6.5 pounds.
The PSA AR-15 Complete Lower is the Magpul MOE Edition that features a quick-adjusting Magpul stock. This PSA lower will accept all AR15 magazines, however, no magazines are included. This quality, reliable lower assembly is reviewed in this video:
Share the post "Get S&W Pistol and AR15 Complete Lower for $379.99"
By Dean Weingarten,GunWatch Blog
The first year of the Trump era National Instant Check System (NICS) has ended with the second highest number of NICS background checks on record. There were 2,586,138 NICS checks in December of 2017. There were 25,235,215 NICS checks for all of 2017. At the current 56 firearms per 100 checks ratio, we can expect that over 14 million firearms have been added to the private stock in 2017*. The number of private firearms in the U.S. is now approximately 418 million.
That is a drop of 9% from 2016 to 2017, but it is 9% higher than 2015. The only year to surpass 2017 was 2016, with 27,538,673, when Hillary Clinton was widely considered a shoo-in to be the next president. The next highest year was 2015, with 23,141,970. December 2017’s numbers alone were the fourth highest December on record, behind 2012, 2015, and 2016.
Prices Drop for Guns and Ammo
The reduction from the overheated firearms market that existed in 2016 is significant. NICS checks dropped by 9 percent. With that drop, prices of guns and ammunition have also dropped. And supply has increased — .22 LR ammunition is being seen on shelves where it had been mostly absent for four years. Bargain prices for modern sporting rifles such as AR-15 clones and good quality pistols have kept the overall numbers from dropping further.
It is a buyer’s market now for Guns and Ammo. Vendors are offering big discounts on Black Rifles such as the Savage MSR line.
*In a year and a month or two, we will know just how many firearms were added to the private stock in 2017. The ATF is not allowed to release the actual manufacture, import and export numbers for a year, by law. Note — there is NOT a 1:1 correspondence between NICS checks and gun sales. About 100 NICS checks are done for each 56 new firearms that are added to the private stock in the United States.
Share the post "Gun Sales Strong in Year One of Trump Era"
We call them “black rifles”, but that shouldn’t refer to all the carbon and gunk on the inside. AR-platform rifles can be maintenance-intensive beasts. But some AR owners make the situation worse by not regularly cleaning important small parts, or by using too much oily/greasy lubricants in the wrong places. A properly maintained and lubricated AR15 can shoot hundreds of rounds (between cleanings) without a problem. If you learn where (and where not) to apply lubricant, you’ll find that your AR will run more reliably and the task of cleaning the bolt and bolt carrier will be less of a burden.
Here is a good video that explains AR-15 Cleaning and Maintenance. In this 30-minute NSSF video, Gunsite Academy instructor and gunsmith Cory Trapp discusses the proper way to clean and maintain the AR-15 carbine. Very knowledgeable, Trapp provides rock-solid advice for AR owners. Along with cleaning producedures, this video explains how to inspect key components and how to function-test your AR before each shooting session.
Share the post "How to Clean and Maintain AR-Platform Modern Sporting Rifles"
Let’s face it, AR-platform rifles run dirty, at least compared to typical bolt-action rifles. The AR15 works by piping gas from the barrel back into the bolt carrier, causing the bolt to unlock and the carrier to move the bolt backward. The “exhaust gas” from the barrel contains soot and carbon. The carbon will form hard deposits on the bolt. In addition, the carbon can combine with lube on the bolt carrier to make a nasty, paste-like sludge. This can be particularly problematic when the black paste pollutes the ejector and extractor recess.
This Editor has inspected dozens of ARs over the years. Other than mag-related malfunctions, the most common cause of AR cycling problems I found was oily gunk in the extractor and ejector areas. Many AR owners overlook these critical areas. Look at an AR that hasn’t been cleaned properly and you’ll probably find black gunk (and small brass shavings) in the ejector and extractor recesses.
If you want to keep your black rifle running smoothly and reliably, you must clean it regularly and follow the correct maintenance procedures. Here are three videos that explain how to properly disassemble and clean AR-platform rifles.
Take-Down and Full Cleaning of AR15 by Jerry Miculek
Here ace shooter Jerry Miculek takes down and cleans an AR-platform rifle belonging to his daughter Lena. This is a good video because Lena’s rifle was “run hard and packed up dirty” so you can see where carbon and grease build up. This 35-minute video is very thorough. Jerry is one of the nation’s top action carbine shooters, so listen carefully to his advice on cleaning and lubrication.
How to Clean Your AR-Platform Rifle
This is a good basic video that shows the take-down and cleaning procedure for a typical AR15. It uses some fast-motion sequences to speed up the story. Check out this video if you don’t have the time to sit through the Miculek video above.
Cleaning and Lubricating AR15 Bolt Carrier Group
This video offers very specific advice on the bolt carrier group, which receives the dirty gas directly from the barrel. Be sure to check the extractor and ejector recesses. That’s where old lube, brass shavings, and carbon accumulate. Follow the directions in this video for lubrication, and don’t over-lubricate the bolt carrier — that will only capture more carbon.
Share the post "Black Rifle Maintenance — AR15 Cleaning How-To Videos"
Can you buy a new firearm for fifty bucks? Yes you can, when the “firearm” is a stripped lower receiver, the key component of an AR15-type rifle. With an AR lower, you can build your own “black rifle” project, which could be a gun for Service Rifle competition, or a specialized varmint-slayer, or a rig for 3-Gun matches — the choice is yours. Once you have the serialized lower (which must be transferred through an FFL dealer), you can build your own project as you see fit, with the trigger, barrel, stock, handguards, and sighting system of your choice.
Right now Sportsman’s Guide is offering a great deal on Anderson stripped lower receivers. You can purchase the lower for just $49.99 ($44.99 for Buyer’s Club Members). These are good-quality lowers, with correct mil-spec dimensions, and precision-machined to ensure drop-in installation of aftermarket components. Crafted from 7075-T6 aircraft-grade aluminum forgings, the made-in-USA Anderson lowers have a hard-anodized black finish. The take-down pin has a standard 0.250″ diameter.
Share the post "DIY Black Rifle Starts with Stripped Lower — Get One for $49.99"
NOTE: Despite the “BLK” in the name, this is a NOT a black powder substitute. This is a modern smokeless powder suitable for a wide variety of popular cartridges.
Hodgdon has announced a new “faster” variant of its popular CFE 223 powder. That’s good news for shooters of small varmint cartridges. Hodgdon’s new CFE BLK (named after the .300 AAC Blackout cartridge) has a faster burn rate than the original CFE 223. That makes CFE BLK ideal for small cartridges such as the .17 Hornet and .221 Fireball. The original CFE 223 propellant was formulated for reduced copper fouling (“CFE” in the name refers to “Copper Fouling Eraser”). New CFE BLK shares this reduced fouling technology which was developed originally for the U.S. military. Many of our Forum members have tried CFE 223 and confirmed that is performs “as advertised” — with less copper fouling that most other propellants. That’s a big benefit for varmint shooters, who may put hundreds of rounds through a barrel in a single day on the varmint fields.
Optimized for the .300 AAC Blackout cartridge, CFE BLK works great for .300 Blackout loads in AR-type rifles throughout the range of bullet weights. Moreover, CFE BLK is perfect for subsonic, reduced loads. In addition, Hodgdon reports that CFE BLK performs superbly in many smaller-capacity cartridges, in particular varmint cartridges such as the .17 Hornet, .17 Ackley Hornet, .218 Bee, .221 Fireball. CFE BLK is also well-suited for the 6.8 Remington SPC and the 7.62X39 Russian cartridge.
CFE BLK Meters Well and Burns Clean
CFE BLK is a spherical (ball) powder. Hodgdon reports the CFE BLK meters well, allowing reloaders to throw very consistent charges every time: “This fine powder meters like a dream and leaves no copper residue, extending accuracy for longer shooting periods, and making clean-up quick and easy.”
CFE BLK Should Be on Dealers’ Shelves in January 2017
Starting in January, 2017, CFE BLK powder will be available in both one-pound (1-lb.) and eight-pound (8-lb.) containers. Check with leading vendors such as Bruno’s, Midsouth, and Powder Valley. By the end of 2016, you should find complete load data for CFE BLK on the Hodgdon Reloading Data Center at www.HodgdonReloading.com.
Share the post "New Hodgdon CFE BLK Powder — Great for Small Cartridges"
If you missed out on some steller deals this past Friday, fret not. Brownells.com still has many products on sale through the end of the weekend. What’s more, you can save an additional 10% by using Code LCX for purchases of $150.00 or more. Today’s daily bargain is an Aero Precision AR upper for $69.99. That’s a steal. Combine that with a $199.99 assembled Bushmaster Lower Receiver (with stock) for a very affordable package. If you don’t own an AR platform rifle, this is a great way to get started.
Share the post "Big Discounts Still Available at Brownells.com"
The NRA America’s Rifle Challenge (ARC) is a new short-range rifle discipline designed to develop practical shooting skills using modern sporting rifles such the AR-15. NRA-ARC is designed for shooters of all skill levels. With all targets positioned at 100 yards or less, almost any outdoor centerfire range is capable of hosting ARC matches. No pits or swinging target holders are required.
The ARC is a close-range, action-oriented discipline. The course of fire features targets placed from seven yards to 100 yards. Some stages also incorporate magazine changes and the use of barricades. ARC matches involve movement, as competitors transition into multiple shooting positions: standing, kneeling/sitting, and prone.
NRA-ARC is NOT limited to AR-15s. Any semi-automatic detachable magazine-fed rifle can be used. There will be three classes of firearms: Iron Sights, Optics Limited (with one non-magnified optical sight), and Optics Open (maximum two optical sights, one of which may be magnified).
5. 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.
