As noted, rifle loads seldom generate 10% propellant compression during bullet seating. Therefore, it is unlikely that, excepting combinations such as 458 Win Mag or 45-70, where long heavy bullets are seated deeply into a nearly cylindrical case, propellant compression will ever be adequate in rifle loads as to compress charge sufficiently so that elastic granule force will contribute significantly to potential for primer blast to initiate bullet movement.
Hence, it seems that a simple test will prove whether primer will move bullet and, if so, maximum likely amount of such movement. If a primed-only test shows no bullet movement, it is unlikely that loaded round will show bullet movement in response to primer blast – since any such pre-charge-ignition movement is apt to result in varying degrees of boiler room enlargement, before propellant ignition occurs (see test results), it is likely that such movement is always detrimental to utmost accuracy.
Since this result is so important, I will repeat it: If primer blast alone does not move bullet in your rifle load without charge installed, it is unlikely that primer blast will move bullet in any normal loading.
Some benchrest shooters attempt to get around the, bullet-movement-equals-variable boiler-room-space, limitation by seating bullets directly against rifling, so that bullet movement requires rifling engravement, which requires significant force. However, this approach may not work, as one benchrest competitor discovered when he failed to charge one case during a match.