OzFclass

G'day John,
You have probably already done this but have you lapped your scope rings to stop the scope being distorted on installation?
If this has not been done and the scope is under stress you will get image/parrallax issues.

AlanF wrote:Now I get it.

And to support what you said about the eye-piece not needing to be locked, I found mine loose to the point of wobbling once, and it didn't appear to have been affecting accuracy.

Alan

If have found if you shoot a very accurate rifle [a 6 PPC bench gun at close range] with a loose eye-piece the group sizes do get bigger.

Keep smiling,

Charlie

G'Day all,
the idea of the rear eye piece being unlocked and NOT affecting groups and Point of Impact is a false.

I helped a guy out one day at the range and his .22-250 with a weaver 2-10x scope wouldn't group better than 2moa and the POI was moving all over the place.

A quick check of mounts bases didn't find anything, I even shot it to no avail. It was only when I went to adjust the eyepiece because the cross hairs were a little out of focus for me that I found the eye piece loose. So much so that there was around 1/8" (3mm) of movement up/down/sideways.

Once focused to the owners eyes and tightened, it shot well under .75moa and most of the shots were cutting with regularity.

So dont be fooled, if its loose it will move, thats why the leupold 36-d series scopes came out with locking rings for the front parallax AO.

Cheerio Ned

Back to the eyepiece tolerances and the fact that it has no effect on accuracy.

Its easy to test. Just setup the rifle and move the eyepiece sideways. You will notice no effect on a properly parallax adjusted scope. This is because the X hairs and objective dont move with respect to each other.
If it does have an effect, start looking at the mounting of the erector/zoom tobe and X hair. They should be absolutely independently mounted from the eyepiece.

Why do some manufacturers have a lock ring ? Because many shooters expect it.

I would ask why do some of the best makers have a non locking eyepiece ? They have done their research and ignored common myths.
A lot of the (mainly US) reviewers and 'experts' on the net have much to answer for.

Peter Smith.