I usually go 150-200. Anything over 200 without a coach/instructor and I'm just making backwards progress, I think. Sometimes I go more, but it's usually because I'll be with friends and we'll do something creative, like a little competition of some sorts. I shoot at "Sharpshooters" in Lorton for you NoVa guys......I'm sure no one wants to be in there longer than an hour since their AC blows. I actually just came back.....I only ever shoot there in the evenings during the summer.
That's for a practice session.....with a training day in a class, I shoot as much as the class requires and never feel worn out until the end of the day. You get breaks all the time in a class, whereas at the range it's not like I'm going to take a seat and talk to someone while I inhale all that toxic dust in a 90*F/60% humidity range, so I kinda just blast through the rounds mag after mag.
When I lived in Vermont, I was mostly into non-tacticool long guns. I've really liked slow-fire long distance rifle work ever since I was a little kid. I could shoot 50 rounds in an entire day and be happy in that setting, but there's no rifle ranges I know of around here.....not to mention I hate Virginia's weather.