SCREWS:
Stock screws that have worked loose are probably the most common cause of inaccuracy in spring piston air-guns. Even a quarter turn loose can translate to significant increase in group size. Most air-guns have one or two screws at the front of the forearm and one securing the action to the stock near the trigger (often one of the trigger guard screws). These must be tight at all times with any lock washers in place. We recommend checking the tightness every 100 rounds or every year whichever comes first.
Barrel pivot screws that have worked loose screws on the front of the compression tube will also affect accuracy on break-barrel models.
Air-gun slotted screws are different from hardware store screws. They require special screwdrivers with a parallel not tapered tip. Use of a regular screwdriver can damage the screw head, the gun, or yourself. Don't over tighten! Any more tension than firm will probably compress the wood fibers and damage the stock, particularly the forearm screws.
SIGHTS:
Open Sights - check that the front sight screw is tight and the sight element held within is secure. Check the rear sight for play. Remember to re-adjust your sights whenever your target distance varies, because pellet drop takes place with increasing distances.
SCOPE MOUNTS
For best results and to prevent damage to your scope and air-gun you should use a scope mount specifically designed for air-gun use. These may have an integral scope stop pin that locates in special arrestor holes milled into the receivers of the some air rifles. Unlike a firearm, spring piston air-guns jump forward and vibrate. Separate scope stops should be used if the scope stop is not an integral part of the scope mount. Scopes can also move through the scope rings but this problem is usually eliminated using the right scope mount or using double faced gummed tapes.
INCORRECT BARREL TENSION
Break barrel air-guns must have the barrel pivot screw tension set correctly. Too much tension and the barrel detent will not consistently lock up and there will be galling of the breech block. Too little tension and there will be blow by at the breech. Incorrect barrel pivot screw tension can cause larger than normal shot groups. The correct tension is the point where the barrel will just stay anywhere on the return arc after cocking.
PELLET SELECTION
Most inaccuracy queries emanate from owners of .177 magnums rated muzzle velocities of about 1000 fps or more. Many manufacturers use the very lightest pellet available to achieve their advertised velocity. You must determine the best pellet (brand, shape, and weight) for your particular air-gun. Every air-gun is different and what works for one air-gun doesn't mean it will work on another air-gun of the same make and model. Don't use old and oxidized pellets or any deformed pellets. Deformed pellets can allow the piston to hit too hard, risking damage, or get stuck in the bore. Only use high quality lead pellets from reputable manufacturers. CHEAP PELLETS ARE FALSE ECONOMY.
THE BORE
Air-gun barrels accumulate fouling, but not in the same manner as regular firearms. Instead minute traces of lead and the air-gun's lubricants from the compression chamber deposit in the rifling. This must be carefully removed by proper air-gun barrel cleaning. We strongly recommend a flexible rod or pull through to avoid damaging the delicate crown or rifling.
Never use regular petroleum based lubricants, gun oils, or firearm solvents because they will attack the seals. Use a gentle degreaser on a cotton-patch and make sure the bore is dry before applying a very light coat of polarizing oil to protect against rust. A good quick fix in the field is to use "Quick Clean" felt pellets which are fired through the barrel every 500 shots.
SHOOTING TECHNIQUES
Hold your air-gun loosely against your shoulder and let it jump around when you fire it. Don't pull it in hard into your shoulder and don't rest the forearm on anything. Let it recoil and vibrate freely. Because this recoil and vibration occurs while the pellet is still in the bore you must hold your sight picture just a little longer to get the smallest groups possible. Trigger squeeze, breathing, and stance are more critical then when shooting a firearm.
HAPPY SHOOTING!
Brihacharan
