Tips for Rimfire Success:
Accuracy Testing and Sight-in

For some people, rimfire shooting is a casual diversion that, at best, keeps the eye sharp for other shooting disciplines. Yet many regularly use rimfire firearms for small game hunting, varmint shooting, pest control, or competition. Regardless of the kind of shooting, you want to get the most out of your rifle or handgun. Great accuracy is part of that goal.

Accuracy
First, let's get the concept of accuracy straight. Accuracy means that all the bullets hit the target relatively close to each other. It doesn't mean hitting the bullseye. Go for good groups first. When you find a combination that has all the hits close together, then you can move the sights to make them land in the place you want.

Testing
Accuracy testing need not be burdensome. All you need, outside of the firearm and some ammunition, is a safe shooting venue with targets set at a known distance, some appropriate targets, and a steady shooting rest (preferably on a bench that allows you to sit). Paper targets are best for accuracy testing. For rimfire sighting, choose a target with a number of small round bullseyes if your firearm has iron sights or a "red-dot" optical sight. If you have a traditional scope with crosshairs, pick one of those sight-in targets that has hollow squares. These make for accurate placement of the crosshairs and improve your load analysis.

Take a Rest
A gun rest can be as simple as a rolled blanket or jacket. Some people use a simple wooden rest made of a couple of 2x6 boards nailed together to form an inverted "T." Of course, there are very nice commercial rests that offer more versatility. The rest should be tall enough to allow you a comfortable position; too low and you'll strain your back. If testing a rifle, slip a sandbag under the buttstock at the point where a sling swivel would mount. Squeezing the bag with your non-shooting hand is a great way to make fine adjustments in your aim.

The rolled blanket is a great choice for handguns. However, don't rest the pistol-rest your arms between the elbow and wrist, with the pistol ahead of the rest..

For rifles, place the forearm-not the barrel-on the rest. If the rest touches the barrel it will induce variables that you don't want. Avoid "canting" the firearm (tipping it side to side) during testing. Keep it vertical to get best results. The real key is consistency. Keep everything-grip, position on your shoulder, trigger pull-as consistent as possible for the shot strings.

Shoot!
Once you are satisfied that you have a good rest and a consistent shooting position, it's time to fire. The distance you choose should be realistic to your shooting sport. Remember, at this point we're looking for a combo that puts the bullets as close together as possible at ranges you will see in the field. You're going to shoot for group size first; if you don't like where the group hits, we'll tell you how to move it later.

With a slow and deliberate pace, fire several 5-shot groups onto different bulls with each load; that way you have enough data to make a valid decision. A three-shot group may look great, but won't be representative of the entire ammo lot or your firearm. A statistical study conducted by our QA department showed that the fewest shots you can fire into one group and have a high level of statistical confidence for repeatability is seven. Your minimum shooting for each ammo type should be one 7-shot or two 5-shot groups. More is better.

What's a good group? At 50 yards, most decent-quality bolt-action sporting rifles with the "right" ammo will put five shots within a inch or less. If you're there, and the rifle is essentially as-issued, you should be pleased. Sporting handguns will usually do under two inches at 25 yards. Dedicated target firearms should do much better.

Once you have some groups, look for the smallest, most symmetrical ones. Note the ammo brand and type that produced the best groups. The reason you test is that many rimfire firearms show a distinct preference to ammo brand and type. Try different ammo until you find one that produces tight groups with a bullet appropriate to your sport. Once you have the desired group, then it's time to move the sights (possible on most firearms) to put those tight groups in the middle of the bull.

Flyers
A "flyer" is a shot that lands well outside of an otherwise good group. It can be a problem with the ammo, or you could have simply muffed the shot. If you know the shot "felt bad" when you let it off, it's okay to ignore the flyer. However, if the shot "felt right" and you can't find any fault with your technique, shoot some more groups with the same ammo.

A damaged bullet could cause the flyer. Repeating firearms, especially semi-autos or those with tubular magazines, are notorious for beating up soft lead bullets. If the gun marks the bullet in roughly the same place every time, accuracy may not suffer. For this reason, group analysis and sight-in should be done the way you shoot in the field. Feed from the magazine instead of single-loading.

Final Sight-in
Here, the distance becomes critical. Rimfire competition can be at 50 feet, 25 yards, 50 yards, or 50 meters (about 55 yards). Flat-terrain varmint shooters should consider a 100 yard sight-in. Fifty yards is a good "generic" sight-in distance if you use one rifle for everything.

Here's something that some iron-sight shooters often forget. The most accurate sight picture with post or bead front sights is obtained with a round bull perch atop the front sight. This is called a 6-o'clock hold. The little sliver of white between the bull and sight is a good way to look for vertical misalignment. You can move the firearm until the sliver just disappears.

However, with this alignment, a "dead-on" sight-in will plant the bullet at the bottom of the black, out of the X-ring for target shooters. If you're going bullseye shooting, set the sights to hit a little high with a 6-o'clock hold. If the bull is 2 inches in diameter, you want the rifle to shoot one-half that distance-one inch high in this case-so the group is centered on the X-ring. On the other hand, shooters who need the bullet to hit exactly to point of aim should set iron sights accordingly.

Let's review the rules of site movement. First, get it in your mind that you want the group to move relative to point-of-aim. Some firearms have rear sights that allow both vertical (elevation) and horizontal (windage) adjustment. Any sight in a dovetail slot has windage-you can move the site in the slot by tapping it with a nylon drift to move it. In some cases, you may have to drift the front sight to achieve proper horizontal alignment.

There are two rules for moving sights to change point-of-impact:

• Move the rear sight in the same direction that the group needs to move. Example: if the group must move right, adjust the rear sight to the right until the group strikes the bull.
• Move the front sight in the opposite direction that the group needs to move. Example: if the group must move right, tap the front sight left until the group strikes the bull.

Trouble-shooting Accuracy Problems.
Sometimes, you can't get a good group regardless of your sight-in technique or choice of ammo. There are some things you can check:

1. Follow-through. Are you jerking your head up to see where the bullet hit? Proper follow-through means holding your sight picture and grip for at least a full second before moving. An old-timer said, "Hold until the bullet hits and cools down!"
2. Unload the firearm and remove the bolt if possible. Check the bolt face for a build-up of bullet lubricant and other residue. Check the back face of the barrel at the same time. Remove any residue
3. If you can remove the bolt, flush the spring area with degreaser to remove residue build-up that can cause inconsistent ignition.
4. Some rimfire rifles have a rudimentary stock attachment system, often a single large screw. In addition, mass-produced rimfire rifles may have considerable clearance between the metal and the wood. Tighten all screws that mount the barreled action to the stock. If the action is still loose in the stock, consider having a gunsmith bed the action in the stock to reduce play.
5. Check scope mounts (or iron sights) for looseness, and correct if necessary.
6. The firearm could have excessive headspace. If found, this is not a user-correctable condition; you need the immediate services of a competent gunsmith or the factory before shooting the firearm any more. Excessive headspace is much more than an accuracy problem; it affects safety as well.
7. Stringing of shots (where the bullet holes are in a line instead of a symmetrical cluster) can be a gun problem. However, the first thing to check is your shooting position. Barrel touching the rest? That will often cause vertical stringing. If you adjust your position and still get vertical stringing with most ammo types, you may have a loose stock (see 3 above). Horizontal stringing can be caused by a stock fit problem, jerking the trigger, or it could be crosswinds. If the latter, wait for the wind to die down. Sighting should be done with no crosswinds whenever possible. If you try to correct for a 20 mph wind at the range on Tuesday, you'll be all over the place when you get to the hunt on Saturday.
8. In revolvers, the barrel/cylinder gap must be no larger that 0.012 inch. An excessive gap can cause vertical stringing due to velocity variation and, worse, could cause a dangerous bullet-in-bore condition.

Last, but certainly the most important, is gun condition There are many old, worn, or abused firearms that are potentially unsafe to fire with ANY ammunition. If Grampa's rifle falls in this category, hang it in an honored place over the fireplace; use a newer model in top condition for your shooting sports.