Troubleshooting Rimfire Rifle Accuracy; Step by Step Illustrated Guide
We've all had one of those rifles that just won't group or shoot accurately. It seems no matter what you do, different ammo, focus on shooting techniques, etc., the thing shoots much larger groups than what it should. You've tried everything to correct it but it appears to just be a "lemon".
Maybe, maybe not. Below is a step by step illustrated guide to take you through all of the steps necessary to identify problem(s) with bolt action rifles that could be causing the inaccuracy you are seeing with your rifle. The steps are designed to be executed in order to insure efficiency and get you back out on the range or in the field as quickly as possible. In some instances, the guide may have you perform an action then return to steps above and repeat a few steps.
1. Insure the scope base and rings are tightened to proper specifications. Refer to the owner's manual for the correct spec. If you don't have that information, 20-30 inch lbs of torque is usually sufficient. Use a torque meter to insure all screws are tightened to spec. Also add a drop of blue locktite to the threads of each screw. Once done move on to step 2.
2. Once the scope is mounted as called for in step 1, closely inspect all areas of the scope including all adjustment knobs, elevation, windage, and parallax. Inspect those and other parts of the scope for looseness. Shake the scope and listen for internal rattling. If any of the above is found it should be repaired back to like new condition before moving on. If there is internal rattling, send the scope back to the manufacturer if the warranty is still good for repair. If not, you will have to replace this scope. If all of the above checks out good, move on to step 3.
3. Make sure the scope is repeatable or in other words insure the scope cross hairs will return to the original point of aim when elevation and windage adjustments are changed 5 moa or more and then returned back to their original position. This should be verified by shooting the rifle at the original position, shooting at the changed position, then re-shooting back at the original position. The center of the original group should be almost exactly the center of the last group with the adjustments back in the original position. This test should be conducted at 50 yards and all shots should be marked in between groups to allow identification of which shots belong to which groups. Use the same target for all 3 groups, this will make comparison of the points of impact easier. If point of impact is off more than one quarter of an inch, the scope probably has an internal problem or is just not designed properly for accurate long range shooting. In this case, change the scope. If POI does return to one quarter inch or less move on to step 4.