I just received a new Lage Max 11/15 upper for my M11-nine. For those that don't follow the latest innovations in the Mac world, this is a 556 rifle caliber upper that was built for the Mac platform RR guns. It's a great product, very well built and the fit and finishe is top quality. The details and specs are on their website if interested. I was fortunate enough to get on the waiting list early in development. The list is somewhere around 1,000 and I was number 33. It's a game changer for Macs. It's currently only available for the M11-nine, but soon they will have them for the M11-a1 and Mac 10. It's now the cheapest way to get into the full auto rifle caliber game. I will give a range report as soon as I get a chance to shoot it.