An Innacurate Rifle: The Diagnoses and the Cures

Were this the best of all possible worlds, we would fire three rifle shots at a target, peer downrange, and see three holes clustered within the area of a dime at precisely the right place. But this is not the best of all possible worlds, in that it has a place for chiggers, bad cholesterol, rabies, and abdominal fat. And in this vale of sorrow, we often look at our targets and see nothing but horror, chaos, and disorder.

In any event, we know that something is wrong, but what? Rather than burst into tears, you should regard this as a heart-to-heart talk with your rifle, which, if you can speak its language, will tell you what ails it.

How to Diagnose—and Cure—an Inaccurate Rifle
If you can understand the indicators, your rifle will tell you what's wrong with it by the way it's malfunctioning.photo by Wheeler Cowperthwaite via flickr.com

Complete Breakdown Your shots are all over the place, and you can't get a group to save your life. There could be several causes. First is a ruptured scope. The way to test this is to put a different scope on your gun and see if it groups better. Second is loose bedding screws on the rifle. Check to see if they're tight. Third is loose ring or base screws. Sometimes, one particular bullet weight will give results this bad. If this is the case, it's usually because the barrel's rifling twist is wrong for that bullet weight.

Consistent Flier Your ammo is almost, but not quite, right for your gun. Usually this shows up as two holes close together and the third one off to the side by an inch or two. At 100 yards, this is not a problem, but at farther distances, it will begin to cause some trouble. It's caused by bullets traveling just above or below the optimum speed for that barrel, causing it to vibrate inconsistently. Hand-loaders can cure it by raising or lowering the powder charge. Non-handloaders will have to try different ammunition.

Inconsistent Flier Problem Most of the time you get good groups, but sometimes you have one shot go astray, and then sometimes all three go where they're not supposed to. Most likely you're flinching, and if you don't think that it's possible to flinch from a benchrest, think again. You can buy or experiment with a sled-type shooting rest, which can virtually eliminate felt recoil, or try putting a soft gun case or sandbag between your shoulder and the butt. Or, if all else fails, get a less punishing rifle.

How to Diagnose—and Cure—an Inaccurate Rifle
How your shots pattern on the target can tell you a lot about what's going wrong with your rifle.

Rising Group Your groups are usually okay, but they seem to keep moving up on the target, sometimes up and to the left or right, sometimes straight up. This is caused by an overheated barrel. When a tube gets too hot, it warps slightly, sending bullets errantly. In addition, the heat waves rising from it give you a distorted view of the target, sort of like shooting through a swimming pool. The cure is easy: Let your barrel cool down. Start each group with a cold barrel and never let it get beyond lukewarm.

Stringing In this situation, your groups string vertically or horizontally. First check the barrel bedding. Most barrels today are free-floating; there should be no contact from 1 1/2 inches forward of the receiver right out to the end. If there is, take the gun in for a rebedding job. The horizontal grouping can be caused by wind at the target that you don't feel at the bench. The vertical groups can be caused by the fore-end jumping on too hard a surface.