Only a few professionals mount scopes correctly. Most people and many gun shops simply fit the scope base and clamp in the scope. Most scopes I have seen, have some or all of the following faults; misaligned with the bore, incorrect or poorly fitted rings, scope mounted to high, poor eye relief, reticule not vertical, damaged tube and the wrong scope for the application.
Selecting the correct scope
This is a substantive subject and one that I will only provide a brief overview. In essence you must have the “right scope for the job”. For example there is no point in having a x25 magnification scope with a 56mm object lens for a .22 rimfire with engagement distances not exceeding 100yrds. A good scope for a modern .22 with engagement range not exceeding 100yrds would be a 25mm tube, 44mm object lens and a magnification not exceeding x12 and also as a good rule of thumb, with a value not exceeding that of the rifle. For classic rifles the scope must be proportion and in character to that of the rifle as well as having the performance. A good example for a Enfield or a Mauser might be a classic Pecar or Weaver scope from the 60’s & 70’s that would permit engagement ranges up to 500yrds
Scope Ring Alignment
Millet scope rings with windage adjustment are prime examples of the difficultly involved in ensuring the rings are parallel for the scope and aligned with the bore. By using the device depicted TVG can eradicated all problems associated with this issue and thus avoid damaging your scope. The rings were fitted using the MK1 eyeball and as you can see are slightly misaligned. Fitting a scope in this situation would potentially damage the scope.
Scope Ring Lapping
Even with the rings correctly aligned with each other and the bore the matting surfaces of the rings do not exactly match. This stops the scope binding evenly with the rings in worse case scenario can damage the scope tube. Using the parallel bar depicted together with lapping paste allows TVG to match the two rings exactly.
This is the most common fault with amateur scope fitting, their are various devices on the market but in my opinion all fail as they do not ensure the rifle and its scope base are vertical first.
TVG uses a vernier height gauge to ensure the rifle is parallel, the scope is fitted and then the scope is adjusted so it is parallel to the rifle, thereby ensuring the reticule is vertical.