Thanks for all the replies. I've seen Armalite's and now Bushmater's, and have just wondered at the effectiveness of this gun. By that I mean the ability to control it in a rapid fire quick engagement setting. I have some concern about how quickly I can get a follow up shot with the increased recoil over 5.56, as well as the overall length as a home defense rifle.
Like I said, ideally I'd like to get to a point where I only had one caliber. This does have its limitations, but comes with benefits as well. My main motivation is simply money. I can't really afford to have serveral rifles over a large range of calibers for a large range of situations, so I am looking for 2 rifles that would be able to handle a great deal of them. Neither rifle may be ideal in any one given situation, but between the two would be able to handle any given work load. I hope to never have to use my rifle to defend my home, or any one elses for that matter, but in looking at the BAR10, the first thing that came to mind was how well it would perform in a home defense/cqb situation.
I do have a little bit of that SHTF concern, but merely think that by choosing one caliber that I can cut costs in reloading equipment, spare parts, brass, primers, powder... yada yada yada. I know its a little out there, but I would like to be somewhat prepared if that situation ever did present itself. In picking one caliber, I am presented with the poblem of overkill/overpenetration in a CQB arena, or lack of knock down power in a hunting arena. I like elk, but don't charish the idea of trying to bring one down with a 5.56.