Nothing that I know of is even close in BC to Lost River Ballistic Technoligies. I believe they offer a J-36 hunting bullet 100 gr over .5(maybe .54 something) amd a 90 gr close to or over .5 . They are solid copper. The problem with them is they are really expensive and Ive heard mixed accuracy results, usually either really good or really bad, although ive heard similar mixed results with other solid copper bullets like barnes. I guess some barrels like em and some dont. I have no personal experience with them. Anyway they have a website i dont remeber it just hit lost river ballistic into yahoo.com and you can find it. I think cabelas sells em too so you can check em out there www.cabelas.com
and go to hunting/optics and then reloading. While your looking at em check out all of thier BCs. Some are insane like a 7mm thats well over .7 .
By the way alot of shooters and hunters believe that unless youre shooting at extreme rannge, an insanely high BC isnt really that advantageous.
Hope this helps.