I wanted a 8.5" as well, ended up going with the 12.5". I got a chance to handle the two of them before I made my choice and im glad I did because I found the 8.5" so short it was dangerous. In racking forward I found my thumb could quite easily end up in front of the barrel. Under normal circumstances it would probably be easy to control that and operate it safe but since I was buying it for defense I didn't want to chance my thumb getting blown of by accident in a stressful situation. The 12.5" I don't have to worry about that and its still very short, iv also heard you can change the stock and have it almost the same OAL as the 8.5"