IMO you can't do better than Beartooth. Check out the 290 gr. Marshall offers several sizes to fit your individual rifle's bore. One of my .444's slugs .431 so I use a .432 bullet. I could also use the .4325. My other slugs at .429 so I use the .432 for both. You want a cast bullet a bit larger than your bore for best accuracy.
Let me know if you want to try some and I'll send you some along with a load or two.