AR-15 caliber list
How about an AR-15 caliber listing challenge?
I'm going to ask each person who reads the thread to add a post with one single factory caliber which is available for the AR-15 and the trade name of an AR or upper in that caliber.
Please don't repeat calibers that were already mentioned or list a bunch of calibers in your post.
It's OK to count military and civilian calibers as 2 different ones (but please only list one in your post) and its OK to include single shot factory uppers. But no wildcat uppers please unless you know a factory which makes them. For the oddball calibers weblinks would be appreciated.
I'll go first with my favorite:
6.5mm Grendel, rifles made by Alexander Arms.
In a few years when the dust finally clears and people start counting their change there is a pretty good chance that President Obama may become known as The Great Absquatulator
. You heard it first here on TFL.