I've put 100 rounds now through my Weatherby Vanguard. It's the basic blued/synthetic rifle in .300 Winchester Magnum. I was thinking of getting the Weatherby Magnum version instead but figured the Winchester should perform very closely since they both share a 24" barrel on this model.
My first 3 shots at the range, barely on the paper, went into 2". Since I was breaking in the barrel, I was scrubbing frequently and running patches. The next 3 were closer together, and I started adjusting the scope to center on the target for break-in purposes. I put 4 more rounds into the target, scrubbing each time and letting it cool. Then I started shooting 3-shot groups.
The first 3-shot group with maybe a minute cool-down between shots was 1.5", which made my extremely pleased since I was shooting into a 10mph crosswind. The rifle was easily able to best that throughout the day. I think I shot a total of 10 single shots and 10 3-shot groups, scrubbing between each of the single shots and then between each of the 3-shot groups and the gun never displayed any bad habits of throwing shots. Bear in mind that was with off-the-shelf Federal Power-Shok 180gr ammo, nothing fancy, I got 2 boxes free with the gun.
My next trip to the range featured Barnes 180gr. TSX bullets and 72gr. RL-22 with Federal 215's, they crossed the chrony at 2920fps which was a little surprising for a starting load, but 10 3-shot groups all went in under 1". Consistent, reliable, repeatable accuracy, and the weather conditions were a little more favorable with only 5mph crosswind at the most.
So no accuracy problems here, to say the least. It's a great gun that fits me much more comfortably than others I had shouldered.