Rifle Accuracy Thieves

By Tom Kelly

Col. Townsend Whelan once said, “Only accurate rifles interest me”. Well, accuracy is one of those relative terms. It can mean different things to different people. Sub MOA or minute of angle groups are a requirement for long range competition shooters. Minute of angle translates to a 1” or smaller 3 shot group at 100 yards. Two inch or smaller groups at 200 yards etc. Most hunters, however, are happy with 1 and 1/2 inch to 2 inch groups at 100 yards from their hunting rifles. We consider this practical accuracy. There are also specific things that can happen to negatively affect accuracy.

Missed Shot

I recently received a phone call from a very nice gentleman from the Kittery area. He was asking for me to help him diagnose a miss he had experienced on a very nice whitetail buck. He said his 7 mm/08 rifle was extremely accurate. We talked further and he related that he rested the barrel on a log to steady his aim, but it looked like the shot went high over the buck’s back. What caused this mishap is something called “Harmonic Action”. It is a vibration in the barrel that happens as the bullet travels down the barrel. This vibration is incorporated into your sights or scope, so it rarely is even noticed. However, when you rest the barrel on a hard object, like a log, it causes the barrel to bounce slightly. This bounce is unpredictable and can cause the shot to go high, low, right or left, depending on where on the barrel the hard surface is. Most people learn this lesson the hard way by experiencing a miss. It is important to rest your rifle on the forend of the stock. The action is bedded or suspended inside the forend without touching. At least that’s what is supposed to happen. Wooden stocks can sometimes warp if they get wet. If this warpage causes the forend to touch the barrel, the result can be the same. The simple test to see if the wooden forend is touching the barrel is to take a dollar bill and slip it between the barrel and forend stock. Slide the dollar forward and back from the point where the barrel is connected to the receiver up to the end of the forend. The bill should slide freely. If it does not, the forend should be relieved by routing out the stock with a curved rasp. There are other simple reasons for inconsistent accuracy. Loose scope mounts are common culprits. Tightening of all screws on your scope mounts should happen well before the hunt. If the screws are found to be loose, they must be tightened. The rifle should then be zeroed again because it will have moved.

The Muzzle Thing

There are other things that can have an effect on your rifle’s accuracy. Frequently, I have seen my clients get into my truck or side-by-side and place the muzzle of their rifle on the floor and the butt of the gun sticking up. Look at your floor-boards sometime. There is sand and grit on the floor, no matter how clean your truck is. The crown on your barrel is very smooth and evenly cut. This is necessary so the gases escaping the muzzle behind the bullet as it leaves the barrel do so very evenly. A nick or scratch on the crown can disrupt the even dispersion of muzzle gas causing a loss of accuracy. These are a few of the most common accuracy thieves. There are of course, many more. I know we have talked about these in the past, but I have had requests recently to review them again. Thank you for the feedback.

Please remember to take a kid or a new hunter with you on your outdoor adventures. I don’t know who said it, but when you take a kid with you on your adventures, it may not change the world, but you may change the world for that kid. See you at the lake or in the woods.

Tom is a Registered Maine Guide. He is the owner/operator of Shamrock Outfitters in Orient Maine with his wife Ellie. He is a retired police officer as well as a retired manager from two major firearms manufacturers. He is an NRA Certified Instructor as well as a Hunter Safety Instructor in Maine, New Hampshire and Massachusetts. You can reach Tom at Shamrock Outfitters (207) 694-2473. Please visit our Facebook Page: Shamrock Outfitters and Properties and come visit us on East Grand Lake

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