I've seen this before with autoloaders. When the action chambers, the sudden stop of the round "pulls" the bullet slightly, just like an inertia bullet puller.
Unless you're running some King-Hell on the edge load, and if the amount of pull seems pretty consistant, I'd be inclined to go ahead and shoot 'em to see if this is a peoblem or not as far as accuracy goes. In that rifle, accuracy isn't likely to be benchrest grade anyway...
The solution may be to increase bullet pull, by sizing the case neck smaller, rather than crimping.
You also might try measuring some factory rounds before and after, I wouldn't be surprised to find that they move a bit, too. I think all autoloaders do this to one extent or the other.
Hope this helps, and please post your results.
Tom