I've seen so many conflicting details concerning the "Tooled Up" achievement and I'm wondering if there is in fact an official statement that has been made by Crytek. Following someone's advice, already having unlocked all of the weapons, I leveled up to rank 50 and rebooted (i.e. played an extra 15+ hours). And, guess what? Still no God damn achievement.
I didn't want to reboot, I have no interest in surfing through the ranks again. I just want this last achievment so I can move on to the next game.