40 to 60 should do it. You will go through 5 to 7 different distances, and you may need half a dozen or so shots at each stage. The practice match is basically to get your trajectory sorted out, and once you get your scope dialed, you just put a couple or three shots on the plate and move on to the next distance down range. We take the whole group (normally 10 to 15 shooters) through each stage, then move to the next... we'll be on the range for about 6 hours, maybe 7. It's a good time to get a new load sorted out, or a new scope or rig, whatever... and of course a good time to meet other shooters from the area. Hope you can make it.
Dan