Even amount of 45# plates? Just kidding. Being able to do 20 reps with 315#, I figured one rep of 405# would be a breeze. Once I hit one rep, I felt like I could keep going so I did. The smith machine was taken so I couldn't practice with that. To do it properly, I should have done 365#, 385# then 405#. I was already finished with squats so I wanted to try it out before I left. I used to train with my buddy a lot before I start going in the mornings. He was big into leg workouts and really could move some weight. He could squat 585# 4-5 times with ass to grass. Training legs with him we always just increased weights with 45# plates.