Did the hunt last year as the driver. We got the last week hunt where the sucess rate was 10% not like the first week where it was running around 90%
my advice, get in early, be prepared for a long shot, and make the first shot count as you might not get a second one, once they get spooked your not going to find them easily.
My choice would be 7mmRM.
Oh and I've spent a fair bit of time in Suffield, don't pick up anything laying around, and its best to avoid any metal things laying around. We saw a few interesting things laying around including a 155 round just laying on the surface. it was a cement head practice round but it had not been found by the range sweep, so the do miss finding other interesting things that are a whole lot more dangerous.