I would prefer going to a range with grass opposed to mats but unfortunately do not have that option. Generally I hit about 2-3 buckets (total of about 100-110 balls) while at the range but am starting to see things the way Croaker24 does.
Most of the times, the first bucket is when I focus on working on my flaws; correct my alignment, weight transfer, etc. but pretty soon I lose focus and/or get way too tired to focus. At that time I probably rush through my shots and 90% of my shots, irrespective of any club will slice like crazy.
To sum it up I believe that if you go to the range with a definite goal and work on it while pacing yourself (as opposed to rushing through the buckets) it may work better.