Why?about all i know about anything like that is that i would want nothing to do with an ultra lite bolt action 50 cal...
I don't want to insult your intelligence here but have you ever fired a bolt action 50 bmg? even with heavier rifles it isn't exactly a joy to shoot. Now you want to put that into a super lite package which is going to magnify felt recoil. Even with a well designed muzzle break it can only do so much.
Is this a rifle you plan on shooting 20 rounds a day with once in a while or do you want to go shoot a hundred or more rounds in an outing and not feel like your shoulder no longer works...
I'm ALWAYS interested in something like that.
Unfortunately right now my finances do no match my interests.
Brand?
My opinion, yes you could probably sell it fairly easily, depending on your asking price.
As stated above, that "Ultra-Lite" will likely feel like an 8 pound sledge hitting you in the shoulder.
If i'm getting a 50bmg, i'm going for something with a little meat to it. I wouldn't trust an AR lower with that, however convenient it might be.