Gerard,
Now, first of all I'm not saying that your or anyone elses bullets have ever produced OSR in a double, but......
Whether OSR exists with a particular rifle can depend on who has examined the rifle.
The question being that would those people be able to see OSR even on a rifle known to have it?
An owner of a fine double is not going to want to see OSR on his pride and joy, and may well be trying not to see any evidence of it, or hoping none exists.
I think that to declare a barrel set of not showing any visible evidence of OSR, the barrels need to be examined by someone who knows what OSR looks like, even very mild cases, and someone who knows exactly how to find it.
IMO this examination should be done by someone not likely to have any bias toward either the rifle or the bullets in question.
I'm not accusing anyone of a cover up, just that I think some people looking for evidence of OSR may not really know precisely what they are trying to see, and in some cases not wanting to see it anyway.