Sure you can, it's just that progress goes much slower. When I finally got into the 500s I was counting 1/2 and 1/4 reps as progress. For example, if I got 525 for 3-1/4 reps for one workout, and later got 3-1/2 reps, that was progress. Keep in mind for me that later could be weeks or months as I'm not naturally big.