I have not. But I have heard of this with Mark V's. The fix is something needs bent or adjusted in the safety mechanism. I would contact a smith or send the bolt to Wby in the off season.
I had the same thing with a recently acquired Mark V in 7mm-08. Thankfully one of the authorized Weatherby service centers is about 40min from my house. I brought it in and they fixed it for free. It works far, far better now.
Does anyone have issues loading Bergers in Weatherby rifles? I'm asking because I couldn't get the 190's to shoot out of my 300 accumark. They shot very good at 100 yards,but when I moved to 200 my groups started to open up. I didn't do a whole lot of testing because I heard that Bergers need to be seated in the lands.
I have a stock accumark so I can't get that close to the lands until I rebarrel. I shoot 180 SST's and Interbonds, and they shoot great.
I think earlier in this thread I told of two 30-378's I owned. One a stock accuark that shot the 210 bergers to 1 moa at 1000 yards. The other was a custom barreled 30-378 that would go close to 1/2 moa at 1000. Both rifles had stock Weatherby free bore and neither of them were close to tje lands by any stretch. I think (if my memory is correct?) They were seated close to .200" off the lands.