I have been a powerlifter for many years and I've been pretty successful, especially in the bench. It's not only the rep range, but the style of lifting that is different. For example, powerlifters lower the bar very quickly to conserve energy, they bench low on the stomach or rib cage and tuck their elbows. There is no concern with isolating the chest.
With that in mind, I have put on more mass then I ever thought possible while powerlifting 285 lbs at the expense of some fat of course. I personally believe the heavy weight forces your body to adapt. I have been benching BB style for 3 weeks (8-12 reps) and high on chest elbows out, and I havent benched over 315 this way. The next 3 weeks I'm benching power style with paused reps. I used to bang out 405 for 5's pretty easy. (keep in mind I'm not 285 anymore). Also I have read a lot of strength journals and books, and the research I have found is that the best rep range for strength and hypertrophy was 6 reps.
Sorry for the long post but here is what I'm going to do (this added a lot of size to me and my partners) 4 sets of 6 reps with the same weight. Pause each rep for quick 2 count. If you hit all 4 sets with 6 reps, move up next week 5-10 pounds. If you miss, repeat the weight next week trying to improve on one of the sets you didn't get 6 on. If you only improve 1 rep you're on the right track, as long as you're improving. This is very demanding and the pauses will be very taxing.
so if your sets are with 300 and your work looks like this
1 set = 6 rpes
2 set = 6 reps
3 sets = 4 reps
4 sets = 3 reps
You have to try and improve at least one rep on the 3 or 4 sets the following week. I hope this helps.
As a note, when I train in the 1-3 rep range, I get stronger, but not bigger. So I dont think 1-3 reps would not be as effective as 6 reps. | 
