I was having several misfires with a new 93 WMR, it was very frustrating at best. I noticed if I cycled the bolt lightly it would misfire, but it shouldn't matter if the bolt is working correctly. I took the bolt out of the gun and put it in a pan with a few inches of water and boiled it on the stove for 10 minutes. All kind of gunk came out of it and it didn't harm the bolt or ruin the finish at all. I shook the excess water out of it (careful it's very hot) and let it dry and lubed it up with some gun oil and put it back in the gun. The problem was gone and the bolt performed perfect. I have about 300 rounds through the gun now since boiling the bolt and all is well. I'm not saying this is a good way to clean your bolt or suggesting anyone do this, it worked well for me and solved my problem. With 7K rounds through yours you might need a new spring inside the bolt, or at least a very good bolt cleaning. Mine was new with only 30 rounds through it.