The best accuracy possible is everybody's goal. The 29-Point Diagnostic is the straightest line to that goal. Many times the diagnostic process itself drastically enhances accuracy. Each diagnostic begins by first measuring all critical tolerances such as the bore diameter, groove diameter and throat diameter and length. With the use of optical inspection equipment the condition of the bore’s surface is checked along with the condition of the barrels crown.
Also important is the consistency of the bore diameter and consistency of the twist. Chamber casting will open windows onto any flaws or irregularities in the chamber and throat. After that the rifle is carefully disassembled. As the rifle is disassembled we look for anything that might impair accuracy, such as poorly torqued scope mount or guard screws or stress torqued into an assembly.
Vibrations are the result of a lack of rigidity or from stress resulting from the poor relationship of a rifle's different components or subassemblies. Through the use of dial indicators these problems are identified and solutions can be recommended. Many times these problems are reduced or eliminated during reassembling. Some problems are not as easy. Poor chamber work can be devastating to good accuracy. The best match grade barrel and pillar bedded stock will never yield good accuracy if your chamber has a crooked, or over size throat.
Each of the 29 points are checked or measured then given a grade of 1 to 5. 5 being the perfect score.
The 29 Point Accuracy Check List
1. The Crown
|2. Magazine Box Position|
|3. Bolt Handle Binding on the Stock or Receiver|
|4. Scope Tracking|
|5. Scope Adjustment Range|
|6.Quality and Condition of Scope Mounts|
|7. Proper Scope Mount Torque|
|8. Scope Mount Stress|
|9. Trigger Guard Screw Torque|
|10. Trigger Guard Screw Firmness|
|11. Action Bedding Flex & Stress|
|12. Barrel Channel, Proper Fit|
|14. Chamber Finish|
|15. Chamber Concentricity|
|16. Neck Diameter|
|17. Neck Concentricity|
|18. Throat Diameter|
|19. Throat Concentricity|
|20. Throat Length|
|21. Throat Erosion|
|22. Recoil Lug Engagement|
|23. Proper Barrel Twist Rate|
|24. Consistent Twist Rate|
|25. Proper Groove Diameter|
|26. Proper Bore Diameter|
|27. Consistent Bore and Groove Diameter|
|28. Trigger Pull, Weight and Creep|
|29. Effects from Firing Pin Fall|