There is a 50BMG AR monster, just got kicked off recently.
The RND guns are so damned sweet to see, JP Enterprises uses the RND matched lower/upper when building their Grade III guns. To think, RND does an AR15 type, AR10 type, and then that god awful 338Lapua monster. It used to be you could see a fair amount of info on their webpage but they redesigned it and it looks like you have to get all info through the mail now. Zeideker has some info on the Edge rifles though.
As for the BIGGEST AR of them all.....
[url]http://www.cobb50.com/index.htm[/url]
A local shop has an AR30 in 338Lapua mag sitting right next to an AR50, funny how small the AR30 looks in comparison to the AR50.
The long range nuts on biggerhammer.net have a few owners of AR30s and the guns are supposed to be quite accurate with the 338Lapua chambering. I'd love to have a 338Lapua but I'd probably stick to 30cal. or 50cal. only, I enjoy being able to load certain bullets for the 30s that I just wouldn't be able to find for the 338Lapua. Same goes for the 50BMG with some of the demilled pulls.