Click on the links below to view more information.
- How Steady Is That Rest?
- Tip For Adjusting Your Sights
- Tips For Mounting Scopes
- Some Scopes Are Just Stubborn
- Correct Sighting-In Procedure
- Boost Power To Shrink Groups
- Sight-In Your Rifle At Short Range
- It’s Called Reticle Run-Out
- Tame Trigger Travel For Better Groups
- Stress, Nutrition
Can Effect Accuracy
Many people don’t realize that a rifle or shotgun recoils
as much as a quarter-inch before the bullet or slug is out
of the barrel.
The concussion caused when the primer ignites the cartridge’s
propellant, can cause an accuracy-killing barrel jump if everything
isn’t cushioned properly.
The experts at Shooter’s Choice suggest that you use the
following checklist before sighting in your rifle or shotgun:
- If you’re shooting from a rest, don’t let the gun recoil
on the sling studs. Leave buffer room between the studs
and the front bag or rest.
- Always cushion the barrel or forearm with something soft
– a hand or pad — to absorb the initial vibration. A hard
rest will cause the barrel to jump.
- Make sure that magazine caps are screwed on tightly.
- Check screws on your scope, sight and trigger guard for
- Make sure the bore is completely clean and the action
and moving parts well lubricated.
- That’s the foundation of accuracy and it’s impossible
to assess a gun if it isn’t clean.
- If you have a variable scope, boost the power. It will
tell you if you’re holding in the same spot every shot and
a higher power will also tell you if you’re holding steady.
Your rifle is grouping low and to the right. Time to adjust the sights. But which way do you move them to correct the flight? Nothing causes more consternation or vacant looks on the shooting range than this dilemma. True, it’s just common sense, but most folks have to think-through the situation to make a decision.
“The rule of thumb is that you move the rear sight in the direction you want the shots to move,” says shooting expert Joe Ventimiglia, president of Shooter’s Choice gun care products. “If the gun is shooting low and to the right, move the rear sight up and to the left.
“If you’ve moved the rear sight as far as it will go
– which can happen, particularly while using iron sights
– then you can adjust the front sight by moving it in the opposite direction of the way you want the shots to go.”
Scopes and adjustable iron sights are calibrated so that you know just how far you’re moving the sight in relation to the distance you’re shooting.
So, you got a new scope and are itching to get it mounted. Installing a scope on a firearm is an intricate and technically demanding process that can be made easier by following some simple guidelines.
Assuming that you’ve got the correct bases and rings for the scope, the first step should be clean all of the screw holes of oil and debris with a quality aerosol degreaser like Shooter’s Choice Quick Scrub III. The product not only blows out and displaces foreign agents but also evaporates quickly, leaving you with a clean, dry working environment.
The bases should be secured to the firearms receiver after coating the screw threads with a locking compound such as Loctite. This ensures that the screws will not come loose with recoil. If the bases are ever to be removed, heating the screw heads with a soldering gun should break the hold. The bottom rings should then be loosely fastened to the base and aligned using a one-inch diameter wooden or aluminum dowel 12 inches long. Placing the dowel in the rings, check for lateral variation and adjust. Next, lap the inside saddles of the rings (top and bottom) with a piece of 320 grit wet-dry sandpaper wrapped around the dowel. This will uniformly smooth the mounting surface and reduce marring of the scope tube when inserted.
Once the rings are aligned, tighten them to the base, place the scope in the bottom rings, mate the tops and install the screws firmly but not too tight. The Shooter’s Choice staff of experts suggests for magnum or long-action firearms that the rings be first coated with rubber cement to prevent sliding during recoil.
Next, if you have a collimator (boresighter), align the scope and bore. If you don’t have one, look down the bore to the target and zero the scope to the same target. Before tightening ring screws make sure that the crosshairs are absolutely vertical and, with your cheek flush to the stock comb, move the scope forward or backward in the rings until the field of view is a bright and complete circle. Now tighten all screws alternately to equalize ring pressure.
The scope should now be aligned close enough to print on a target at 25 yards. Make any individual adjustments at that range until the scope is absolutely zeroed, then make further adjustments at 50 and/or 100 yards.
How many times has it happened to you — shoot a group, make the necessary adjustment to the scope but the next shot flies right back to the original group. The natural reaction is to doubt your marksmanship, or the scope reliability.
But don’t belittle yourself or your equipment right away. Fire at least three shots from the new position (after adjustment) before making any more moves.
“In some scopes the adjustment wheel actually rides against the inside of the scope tube,” explains shooting expert Frank Ventimiglia, vice-president of Shooter’s Choice gun care products. “So the first shot after making an adjustment might not register because the wheel never turned. Usually, though, the recoil from that first shot will dislodge the wheel and adjustment will be correct for the next shot.”
It’s fine to have the dealer install and even boresight a new scope for you, but the actual sighting-in process must be done by the person who will be using the gun.
“It’s common sense, really, but something that a lot of people tend to overlook,” says shooting expert Joe Ventimiglia, president of Shooter’s Choice gun care products. “Everybody looks through a scope from a slightly different angle. The shape and size of of a person’s face, the strength of vision and the position of the head with the cheek against the stock comb are all variable factors.”
Once the scope is boresighted and you’ve determined eye relief (usually about 3.5 inches), loosen the ocular lock ring and adjust the ocular ring counter-clockwise until the crosshairs look fuzzy. Now back-focus until the hairs are sharp and tighten the lock ring again. This adjusts the scope for the master or aiming eye.
Start the sighting-in process at 25 yards. With most scopes one click will move bullet impact 1/4-inch at 100 yards. But remember that at 25 yards that adjustment is quadrupled, meaning that it will take four clicks to move impact a quarter inch at 25 yards. For example, if the initial group is two inches low and one inch left at 25 yards you need to move the vertical adjustment knob 32 clicks up and the windage adjustment 16 clicks to the right.
Always shoot three-shot groups before making an adjustment. Due to interior design, some scopes will not always follow the adjustment you just made until a shot has been fired. Further adjustments should be made at hunting ranges but in an emergency the 25-yard zero can be used. Centerfire rifles zeroed dead-center at 25 yards will usually print 2-3 inches high at 100 yards and be dead-on again at 220 to 240 yards. Shotgun slugs dead-on at 25 yards will print 2-3 inches high at 50 yards, about a quarter inch lower at 75 and virtually dead-on again at 100.
Used properly, a variable-power rifle scope can not only tell you a lot about your rifle but also about yourself as a shooter.
Sure, cranking up the power comes in handy when you want to check out the rack on that buck that just stepped out on the other side of the bean field. But it also has other uses.
“Increasing the power of your scope will also help shrink your groups at the range,” says benchrest shooter Joe Ventimiglia, president of Shooter’s Choice gun care products.
“With the increased resolution you will be able to tell if you’re holding in exactly the same place every shot. Increased resolution will also show quickly if the crosshairs are moving where at a lower power you might have thought you were holding rock-steady.”
The increased resolution might not be as important with a rifle that shoots into two inches at 100 yards as it would be with a tack-driver. If you miss your hold by a quarter-inch with a two-inch rifle, you’ve only increased your group by 25 percent. But miss by a quarter inch with a rifle capable of half-inch groups and you’ve doubled the groups.
You’re aware that you may encounter 250-yard shot while hunting but the only shooting range available to sight-in your rifle is 50 yards long. How can you sight in?
“First you start with a clean bore and a clean, lubricated action,” says benchrest shooter Joe Ventimiglia, president of Shooter’s Choice gun care products. “No gun will shoot accurately or consistently without a sanitary bore.”
When the accuracy foundation is laid, set up your target at 25 yards for a scoped rifle, 12.5 yards for one with iron sights. The short range makes spotting and adjustments easy – and at that the same time you are approximating where the bullet will strike the same target if it were 230-280 yards down range.
“In some hunting calibers where a bullet prints at 25 yards will roughly be where it prints at 220 to 230 yards,” says Ventimiglia, who comes from a family of riflemen.
Because your sights or scope are mounted on top of the barrel, above the actual line of sight, your gun is positioned to shoot slightly upward to compensate. “The bullet leaves the bore in such a manner that it actually rises above the sight line, travels in an arc and drops back below it as gravity works on it down range,” Ventimiglia says.
Ballistics charts show, for example, that scope-sighted .270 firing 130-grain factory loads at 3,100 feet per second, zeroed at 25 yards, will group three inches high at 100 yards, four inches high at 200 and dead-on at 275. A similarly scoped .30-06 shooting 150-grain factory loads at 2,700 feet per second zeroed at 25 yards will be almost three inches high at 100, a bit over two inches at 200 and back at the point of aim at 250 yards.
The gun should be fine-tuned at 100 yards, but the shorter range sighting will get you close if that’s all that is available. One caution: When you sight a rifle, the resultant accuracy pattern is good only for that exact configuration of scope or sight, load and bullet type. Any change in sight height, load or bullet type will grossly exaggerate differences down range.
If you use a variable-power scope with a wide range of magnification, you’ve likely encountered a problem known as recticle runout.
Basically, it means that the rifle’s point of aim is an inch or more higher when the scope is set at its highest power compared to when it is set for the least magnification.
“It really isn’t a major problem,” says shooting expert Joe Ventimiglia, president of Shooter’s Choice. “If the difference in point of aim isn’t too pronounced – two inches or more means the scope is out of alignment – a target shooter can simply sight the gun in at the scope’s highest power, since that’s what he’ll likely be using most.”
“A hunter would also sight in at the highest magnification since the error between points of aim decreases at closer ranges and will be minimal when aiming at the vital area of a big game animal.”
As each shot is discharged the trigger will usually move beyond the point where the hammer was released. How important to accuracy is something as simple as trigger movement after a shot? Plenty.
“Even this little bit of extra movement causes the firearm to move a bit while the projectile is still in the barrel, which will throw the shot somewhat,” says shooting expert Joe Ventimiglia, president of Shooter’s Choice gun care products. “That’s why bench rest and target rifles and some custom guns use a trigger stop – a small screw installed in the back of the trigger guard that actually stops the overtravel of the trigger shoe.”
Food, stress and physical activity all have an effect on both breathing rate and pulse – two key factors in accurate shooting. The old suggestion of taking a deep breath and exhaling a little while you press the trigger is relatively easy to accomplish. Controlling your heart rate is more difficult.
“Heart rate is lowest in the early morning, before food. Research by shooters has shown that eating of even simple food, such as a banana, will increase heart rate at least 10 beats per minute,” says shooting expert Joe Ventimiglia, president of Shooter’s Choice gun care products. “Coffee or a sugary carbonated drink will often cause an increase of as much as 50 beats per minute.”
Sugar, caffeine and carbon dioxide are virtually equal in their influence on heart rate. Tobacco, the excessive use of salt, stimulants, alcohol and refined white flour have cumulative corrosive effects on blood vessels, causing them to stiffen, which causes the heart to pump faster to deliver sufficient oxygen to the system.
“A good daily multi-vitamin combined with extra amounts of vitamins C (6 to 8 grains per day), A,B nd D and at least 2,000 international units of E may help improve eyesight and mental clarity to the point that shooting scores will improve.”