Originally Posted by Spadona
Be careful of the UAR. From what I hear, low/mid caps don't fit it, and they only take hicaps (this may only be the case for the first version, unsure about the second version).
If you do decide to get it, make sure to ask about its mag compatibility.
I have a version two UAR, its was quite finicky with the mags i had, but there is a mod for the gun that allow it to take any mag.
Took ten seconds and it takes all brands of mags now.
The neat thing about the uar is there is a spring right above the mag port, so when you hit the eject button, the mags op out super nice