Many folks have different ideas about accuracy. Absolute accuracy is, of course, all shots in a single hole matching the diameter of the bullet.
That doesn’t happen unless you fire a single shot, although just the same, the AR-15 rifle may be an accurate platform. A few years ago, I was the proud owner of a precision, bolt-action .223 Remington-caliber rifle. With its heavy barrel and 20-power scope, the rifle was very precise. It was no mean feat to place three rounds of Federal Match into a .5-inch group at 100 yards.
I also owned a good quality, although ordinary, 16-inch barrel AR-15 carbine. I mounted an ATN scope and discovered, the Black Rifle would do 1.5 MOA at 100 yards. Later, after acquiring a Daniel Defense rifle and stuffing the magazine with Federal Match, I discovered the rifle would group three rounds into 1-inch—not some of the time, but all of the time when I did my part.
I traded the bolt gun and never looked back. All AR-15 rifles are not created equal, and all may be improved. Some may be brought to an uncanny high level of precision.
Let’s look at where to begin.
The receiver is a two-piece design. The fit is not always tight and can be improved considerably. An AccuWedge is the best $4.00 you can spend. Seat the AccuWedge in the rear of the receiver behind the disassembly pin.
We all use adjustable stocks these days, and they are great for adjusting the length of pull, although not as great for precision.
- A true precision rifle stock is a good choice.
- Check the lock nut on the stock. Use low-strength Loctite to tighten that part. It works well and stabilizes the stock without replacement or impeding function.
- Another important choice is to choose a buttstock that features a flat toe. A triangular toe is less effective for prone fire and true precision fire.
Precision rifles demand a consistent grip. The standard grip is fine for most work. Some prefer it for tactical work because it is easy to slide your hand off the grip to the magazine release. For precision shooting, a standard grip leaves much to be desired. The Ergo Grip makes a world of difference.
The next problem is handguards. The handguard of the original rifle was two pieces. It was okay, although it really did not encourage precision shooting. I found quite a few handguards at Cheaper Than Dirt!, including free-floating models.
You may not need a quad rail for precision shooting, as it is more important to keep a comfortable grip on the rifle. Free floating not only looks good, it enhances accuracy by removing pressure that could be placed on the barrel and effecting accuracy with changes in environmental conditions or hand pressure. That is another option that looks simple and certainly is not beyond the skills of a careful and patient home hobbyist. The handguard on the rifle may or may not be precision grade, but a change should be beneficial.
The AR-15 trigger is pretty simple. It butts into a notch in the hammer. Press the trigger, and it moves out of the notch and the hammer flies forward. The hammer strikes the firing pin, and the rifle fires. While you press the trigger, a lot is going on.
- The bolt cycles and resets the hammer.
- The hammer returns, yet the trigger is still pressed.
- The hammer catches the disconnect.
- The trigger then moves back into the hammer as you release it.
Never file, polish or stone the trigger unless you really know what you are doing. For instance, stoning the sear is a common way gunsmiths used to, and many still may, perform a trigger job. However, given the accuracy and speed of CNC machines, you’ll get a better, more reliable outcome, by simply dropping in an after market trigger. Modifying the trigger by filing or stoning, may cause slam fires or more than one round to be fired per pull of the trigger which would create an unsafe condition and may cause you to run afoul of the law. While I have never experienced or witnessed either of those, what I have seen from a bad trigger job is pretty sad, and that is a failure to fire. The scenario played out like this. Rack the bolt, and press the trigger. The rifle fired but it did not reset. Rack the bolt, fire, press the trigger—no bang!
By far, the best thing to do is replace the AR-15 trigger with a Timney or other high-quality unit. It will be money well spent. The last Timney I installed not only went in without a problem, it also broke at 3 pounds very cleanly. I recently tested two good-quality AR-15 rifles.
- One exhibited 6 pounds of trigger compression, which is about average.
- The other broke at a heavy 9 pounds.
Precision shooting is not in the cards. The rub is that the rifle with the heavier trigger was my favorite and the one I would most likely fit with a match trigger. As a semi-related side note to the multi-fire per press of the trigger scenario, no matter what the cinema depicts our semi-auto AR-15 rifles do not have full-auto bolt carriers and are not thus designed for full auto. For AR’s with the capability to fire full auto, the carrier must be purpose designed for proper functioning, but are otherwise generally identical.
The AR-15 barrel is simple to change—just a barrel nut. The choice is between 16 or 20 inches—it almost goes without saying that you will want to choose a match-grade barrel to wring out the best accuracy. The 20-inch barrel delivers more velocity and precision both are essential to long-range success. The variations in twist and taper are endless, so the choice is yours. That is a personal choice, and unless you have a real need for a lightweight rifle, the 20-inch barrel makes a lot of sense.
Most precision shooters favor a 7-, 8- or one-turn-in 9-inch twist. The original 1:14-inch Armalite barrel turned out some RPMs, but was designed at a time when the military was using shorter and lighter bullets. Given today’s longer and heavier options, a 1:9 stabilizes anything I need to stabilize, including the wonderfully accurate Federal Gold Match 77-grain loading—a bit unusual because the 1:9 typically will stabilize up to a 75-grain bullet, but just at the edge of its effective envelope. Consider a 1:8 twist for the best all around compromise or look to the military, which uses a 1:7 with it 62-grain M855 cartridge.
The sights are very important. Combat sights are great for combat, and precision shooting demands something more advanced. We will cover optical sights in another installment and, chances are, you will not use iron sights at all.
However, many matches and different levels of shooting demand iron sights. The Magpul MBUS rear sight gives excellent results on every rail gun I own, but is designed as a combat sight and normally employed when the primary optic fails. Instead look for offerings such as Armalite’s National Match sights and components.
Remember, a tiny fraction of movement can result in a one-inch miss at 300 yards. You may want to properly sight in the front sight, leave it in place and then Loctite it there.
I’ll leave you with a final note on ammunition selection.
- Burner-grade, steel-case ammunition is okay for practice, but never gives stellar accuracy.
- Federal Gold Match and very few other loads will serve well for precision shooting.
- Federal American Eagle FMJ loads are accurate enough for meaningful practice
- You should handload for optimum results. However, match-grade loads and monolithic designs will carry the day for most.
So what have you done to make your AR-15 the precision gun of your dreams? Tell us all about it in the comment section.