I shot my first "Production" division match a couple of weeks ago. I have six mags, and the most I needed on a single stage was 4. However...because the range was very dusty & sandy(no grass), I found that I had to disassemble and thoroughly clean each mag I used before the next stage so that I'd always have enough. If I had a few more mags, I could have comfortably gone a couple of stages between cleanings. Better to have too many than not enough.