by Wapiti » 20 Aug 2026, 7:37 am
9.3's experiences have inadvertently brought up a real issue.
Just to bring up a subject from another thread about stud type turn-in mounts with the two opposed rear windage screws.
These allow you to keep the scope windage adjustments virtually on-centre inside the scope tube.
So important for the security of the zero, especially in recoiling rifles.
A rifle is a heap of individually-made bits from different machines and even places put together hopefully in a straight line.
With the latest "cheaper is better" rifles nowadays, steps to keep everything straight is often out of whack, and anyone who's set up a barrel or action up in a 4-jaw chuck in a lathe with dial indicators on both ends, inside and out, will tell you that a few thou at one end is a big deal at the other end, let alone at 100yds or 4x more at 400.
That's why the term "blueprinting" was dreamed up to describe making a rifle to a straight line of bolt, action and bore, and take the stresses out.
The craze nowadays of (mostly cheap) rifles only having the option of chucking yet another wildly toleranced, drilled-off-centre picatinny rail on top, then another set of machined with out of tolerance clamp mounts on top that compound the tolerance issues, that cannot be adjusted, shows this up bigtime.
But there have been a few rifle brands made in the old designs, like Zastava and a few others, that have drilled the action mount holes off centre to the bore centre-lines. As well, threaded the barrel-action threads off-line.
So the craze for heavy, unnecessary 30mm tube scopes with more internal adjustment becomes even more necessary to get scopes zeroed on cockeyes action/mounts.
The adjustable rear twin-windage mounts align the scopes with the bore and still remain within centre of the windage.
Up-down is also important, but with the craze for shooting longer range, getting things straight has now been bastardised by 20, 30, 40 MOA ski-ramps for rails.
One thing not often said is, that you want a very nicely machined set of internals, made from nice hard quality metals to repeatedly wind them up and down to make this work over time, as well as hold zero still at the extreme end of the adjustments.
Groups open up wildly and people write it off as wind, the moon, Earths inconsistent rotation, the magnetic north changing or a plane going over or some other excuse but never consider the inconsistency of the springs and detents squashed together in cheap gear.
"The only way to avoid criticism is to do nothing, say nothing, and be nothing."
Aristotle.
Regards G,
AKA Dr. Doolittle