315lb Back Squat for 3 sets of 5 reps

Hit 315 for the first time in working sets. (6 plates)

Back when my working sets were around 280 I managed a 1RM (1 rep max) of 340.

I wonder what my 1RM would be now?

Seeing as how my goal for the year is a 400lb back squat, I'm making pretty good progress.

As soon as my back pain goes away, or I get clearance from the doctor, I look forward to resuming deadlifting.