In an attempt to answer your question, I am going to risk drawing a compairison to a common problem that happens with high power centerfire rifles, so forgive me if this is a sin. Anyhow, in high power center fires, one or two or all of the screws that secure the action to the triggerguard and floor plate in general sometimes back out. This will cause the rifle to plant rounds all over the map. What is so hard to detect is that a lot of shooters never think to check this most basic of areas to solve an accuracy problem. Especially a problem that has suddenly appeared in an otherwise historically accurate rifle. I have first hand experience in passing over checking the screws for correct tightness and have been driven out of my mind in trying to find what the problem was. Having said all that, I would suspect that if your wedge was dislodged and not seated as normal the barrel would be lose and that would cause an accuracy problem. In adition, I would think that whatever harmonics are established from shot to shot in a correctly wedged barrel will be completely lost in one in which the wedge has worked its way free to some degree.
