I agree that the metal expand and contract, a simple solution will be a scope with a carbon fiber body.
Where I shoot we donít have subzero temperatures so I donít have your experience but how about a different approach?
Did any of you made tests to support that thesis?
My belief is that the biggest factor in the differences that I read here are related with light/contrast and not
temperature and they are related.
Rod and all others with March scopes buy a 55mm UW filter attach it to the scope and experience differences off 5 yards at 55yards.