Very low reps (1-4) at a high resistance (85-100% of a 1-rep max) is the standard powerlifter workout. But usually you'd do that for many sets. Lifting a 1RM for a single set seems either grossly inefficient (I have a similar max and it takes me 6 warmup sets just to get into the 405+ range), or he's risking injury by not warming up enough.
You're ridiculous. You can say 315 is achievable in a year. 450 lbs doesn't even get on the charts for any weight up to 310 until intermediate level according to this chart [0]. Nobody with any sense considers themselves to be an 'intermediate' lifter after one year.
These are self-reported numbers mostly from novices on the Internet. I can assure you these do not represent consistent and specific training for this lift.
One order of magnitude is a mere 45 lbs deadlift. Thus the poster must be horrifically weak. He must have wrote that from the nursing home, I'm sure the nurses love it that he spends his days quietly posting nonsense on the internet instead of bothering them.