I have a Blaser R93 and one of the things I like about it is that it breaks down easily and that it should return to zero when put back together again. In saying that I'd always harboured the suspicion that when you take the scope off and on again things might move around a little. So, yesterday I was at the range and I had 7 rounds of a 165 grain Sierra Gameking load remaining. My feeling was that they were not quite fast enough to be deer legal and I'd never been able to get any more of the bullets and so didn't develop the load any further. So, I decided to shoot them at the target and to remove and replace the scope after the first three shots, it was a 100m range. Now, this was the best target I shot all day as I was concentrating, all my other targets were blighted by fliers, and so the only flier is at the bottom right corner of the group, it was the 7th shot too so I wish I'd stopped at 6 :-) However, it would seem to demonstrate that removing the scope does not result in a significant change in the POI and as you can see it is possible to shoot a 2 inch group even when the scope is removed half way through. It was also the case that all 7 rounds were shot in pretty rapid succession with no time for the barrel to cool and so on.
I know it isn't an example of prime marksmanship but it does seem to support the position that there is no shift in POI when removing/replacing the scope on the R93.