7 Rifle Setup and Care Mistakes that Ruin Accuracy

Every year, usually just a few weeks or even days before deer season, someone will call me with a rifle problem. They’re trying to get ready for opening day and things are not working out. Typically, the problems revolve around sighting the rifle in, poor accuracy, or a rifle that will not even function. In most cases the shooter is the cause of these problems. Here are the seven most common ones that I’ve seen, and how to avoid them.

Check your rifle and resolve these common issues before season so that you can make the shot when it counts. Image by Realtree

1: LOOSE ACTION SCREWS

Most bolt-action rifles have two screws holding the barreled action in the stock. One is generally located behind the trigger guard and the other just forward of the magazine box. When deer season is over, hunters who care about taking care of their rifles often disassemble them and remove the barreled action. This is smart because debris can wedge between the barrel and stock and create a pressure point that can alter point of impact or the rifle’s ability to shoot with precision. Moisture can also collect between an action and a stock, and of course, moisture can lead to rust.

The mistake hunters make is during reassembly. With most bolt-actions those two screws need to be tightened to a specific torque setting. If they’re too loose or too tight, the rifle can perform differently or poorly. When you’re putting your rifle back together consult the owner’s manual for the proper torque setting. I’ve seen loose action screws cause 100 yard groups to triple in size. If your rifle is not shooting up to par after assembly this could be the issue. In fact, anytime your rifle is not shooting to its potential it’s always a good idea to check the action screws first.

Check to make certain your action screws are torqued to the correct setting before sighting in. Image by Realtree

2: LOOSE SCOPE BASES

I was working with a group of gun and outdoor writers at Gunsite Academy, and everyone was shooting rifles that came with a Picatinny scope rail pre-installed. Before the first day’s shooting was over, two of the rifles had lost their zero because the scope rail had worked loose. By the end of the second day, the same problem had occurred with every rifle. Now you might be quick to blame the gun maker, and while it’s partly their fault, the real fault was with the shooters. In fact, this is actually a very common issue.

Manufacturers have three choices when it comes to providing a scope rail with a rifle. The first is to include the scope rail in the box. The problem with this approach is if the dealer puts the rifle on the rack, potential customers will not know that it comes with a rail. If the manufacturer installs the scope base — torqued to spec and thread-locked — and the end user wants to use different mounts, they might struggle removing the rail and end up cussing the manufacturer. Most manufacturers just snug the rail in place. That way, it’s visible to shoppers, but it’s also easy to remove or attach correctly.

Never assume a manufacturer installed a scope rail correctly. You should check with the scope base/mount manufacturer for torque specs and apply some thread-lock to the screw threads. In the absence of manufacturer guidance, torque scope bases and rails to 25 inch-pounds.

3: SCOPE RING HEIGHT & RING MISMATCHES

When hunters purchase new riflescopes, they often mount it themselves. That’s fine if you know what you’re doing, but there are all sorts of problems that can occur when mounting a riflescope. You can mount it too low, preventing cartridges from ejecting because they impact the windage adjustment turret. The scope’s ocular housing might interfere with the bolt, or the objective housing could touch the barrel. Mount the scope too high and you may not be able to establish a good cheek weld for comfortable shooting.

Manufacturers generally offer scope rings in low, medium, or high configurations. In most cases, you’re better off using the lowest rings possible. The problem is that “low,” “medium,” and “high,” are subjective descriptions that do not relate to an industry standard. Fortunately, most manufacturers list scope ring height in inches, but pay attention because it can reference the distance from the base to the bottom of the scope or to the center of the scope tube. You might need to do some math, but make sure the scope objective is at least 1/10th of an inch above the barrel. Barrels vibrate during recoil and scopes mounted too low can contact the barrel.

Always purchase bases and rings for the model rifle you are using and double check to make sure all mounting screws on both bases and rings are tight. Image by Realtree Media

Always purchase bases/rails and rings for the exact model rifle you have. And never mix match rings, as this could lead to mounting the scope un-level with the barrel and could damage the scope’s tube or internals. It can also make it nearly impossible to sight in the rifle. Hunters often skimp on scope bases and rings, but they’re one of the most important components. If the base does not perfectly fit the radius of the action, it will work lose. If you have used the rings over and over with different scopes, the screws become worn and will not hold tightly.

4: BORE FOULING

The military is to blame for the notion you need to clean your rifle every time you shoot it. In basic training, if we shot a gun, we cleaned it. Sometimes we cleaned guns even if we didn’t shoot them. The task was not as much about keeping guns clean as it was about teaching soldiers how to take care of their weapons. I don’t wash my truck every time I drive it, and I don’t clean a rifle’s bore every time I shoot it. However, sometimes you need to clean a rifle’s bore because the fouling can impact performance.

Aside from a situation where you know debris or moisture have found their way into your barrel, there are basically two schools of thought when it comes to bore cleaning. The first is that you clean a rifle’s barrel after every shooting session. The other is that you only clean a barrel when precision starts to degrade. Both are acceptable, but there are some things you need to keep in mind.

If you clean a barrel after every shooting session, the first shot from that clean barrel will almost always strike differently than following shots. Also, with some clean barrels — especially barrels on inexpensive rifles — it can take several shots for barrels to settle down. If you only clean a barrel when you start to see accuracy issues, it’s a good idea to know the point where that happens. I once had a fine shooting .257 Roberts, but predictably, around shot 27, the rifle began shooting poorly. I knew I needed to clean it before then.

If you store a rifle with a fouled bore for a long time, season to season, especially in humid environments, the copper fouling can oxidize, and this can negatively impact zero and precision. If you pull your rifle out of the safe to get ready for deer season and it is not shooting up to par, you might need to clean the bore before you spend money on a new scope or start cussing.

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5: CORRODED CHAMBER

This is another maintenance issue that can be a hunt killer, especially if it happens at deer camp, like it did with a guy I know. He always checked his rifle’s zero at camp the day before opening day, and in this instance after he fired his first shot, he had to beat the rifle’s bolt open. When he did the cartridge case failed to extract. It was stuck in the chamber. Unfortunately, he did not have a cleaning rod and spent opening day looking for a gunsmith.

This problem occurs because a rifle’s chamber gets wet while hunting and the hunter fails to clean it. When he puts it away, corrosion sets in. There’s usually not enough corrosion to keep a cartridge from chambering, but when the cartridge stretches after firing it becomes stuck. Sometimes, like with the guy I know, the bolt opens, and the extractor pops off the case rim. Other times, if the corrosion is really bad, the bolt won’t open. Always dry and lightly lube your rifle’s chamber after you’ve been out in very humid or wet conditions and never wait until you get to deer camp to check or zero your rifle.

6: SUPPRESSOR ISSUES

Suppressors are becoming very popular for hunting, but there are some things you need to understand about them.

• If you zero your rifle without a suppressor, you’ll need to re-zero it with a suppressor. There’s always a point of impact shift.

• Make sure your suppressor stays tight. It can work loose with shooting, and this can alter point of impact and even damage the suppressor.

• Don’t forget to check caliber compatibility. Never use a suppressor of a smaller caliber than your rifle.

7: WRONG AMMUNITION

SAAMI (Sporting Arms and Ammunition Manufacturer’s Institute) publishes standards for the manufacture of ammunition. They dictate cartridge dimensions and pressure. SAAMI is the reason .30-06 ammo from any manufacturer should safely function and fire in any .30-06 rifle. SAAMI specifications also list rifling twist rates. Twist rate is important because it determines bullet stability, and the long and heavy bullets with a high ballistic coefficients (BC) so popular these days require fast twist rates. The problem arises when a manufacturer offers a load using a bullet that needs a faster twist rate than SAAMI specifies. This results in bullet instability and inaccuracy.

Not all ammo shoots well in all rifles. Match your bullet weight and design to your rifle for maximum accuracy. Image by Bill Konway

It’s very common with the .223 Remington, for which SAAMI specifies a rifling twist rate of 1 in 14 — because some manufactures offer some .223 Remington rifles with faster twist rates, and some manufacturers offer .223 ammo for those faster twist rates. If you own a .223 Remington rifle with a SAAMI specified 1-in-14 twist rate, you might experience accuracy problems with heavy-for-caliber, high-BC bullets.

It can be an issue with other cartridges, too. For example, even though the most common twist rate for modern .308 Winchester rifles is 1 in 10, SAAMI specifies a 1 in 12. If your .308 Winchester has a 1-in-12 twist rate, it might struggle to shoot a load with a heavy bullet accurately. If you’ve opted for a new hunting load with a heavier bullet and the precision is less than acceptable, consider a different load with a lighter – shorter – bullet that your rifle’s twist rate will stabilize better.

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