Nothing wrong with those, at all. Windham is the former Bushmaster crew and factory, prior to Remington and their huge conglomerate buying the name, and moving it to New York. I bought my son the MPC model back in '12, and we put that thing through the torture! He and his friends would take it camping on weekends with a case of 1000 rounds, and come back with nothing but my empty mags. I bought him an Aimpoint for it a couple years later, and plinked with it at the range, it is dead accurate. I bet, conservatively, he has 8 thousand rounds through it. Very, very few people ever get that many rounds through an AR, in reality. The only thing we have done to it was put in a different spring and buffer. Great little rifle.