Advanced got in, but hasn't posted yet they "short" comp so keep an eye out for that. It's similar in design, you just loose a section of porting. Not sure how it compares in performance to the long. Also talk to Mark at Immortal Arms as he is a dealer now that will be stocking mags - I know he has some in stock now, just not sure the sizes And nobody that I know of have spent the $ on the big Tooth mag to see if it works Sent from my SM-G955U using Tapatalk