Some of the numebrs here are slightly inaccurate.
They select annually 100 of the best shots from across canada, and bring them to Connaught ACNSTC for the six-week CL Marksman. Aside form the normal CL course material, they spend a lot of time on the range with the C11 5.56mm bolt action rifle, shooting from 100-600 yards. Of these, the top 36 are selected for next year's CLI Marksman course.
CLIM is also run at Connaught. It's a seven week course, the last week being the Dominion of Canada Rifle Association competition at connaught ranges. It's a civilian shoot. During the course, the cadets will also (varying from year to year dependant on range availability) travel to PEtawawa and Borden for other competition shoots.
Of the 36 from CLIM, the top 18 are chosen, plus the best 3 from that year's Bisley team, to form the next year's 21 member Army Cadet National Rifle Team. So 18 new cadets, plus 3 returnees.
I did CLM in '02, and CLIM in '03. They were both great camps. I had to miss the last week of CLIM because of a family thing, and so did not have the opportunity to go to Bisley. My younger brother did CLM '03 and CLIM '04, but got in some minor trouble on CLIM, and was bumped off the selected team, even though he had shot well enough to qualify, which was unfortunate. I guess my family just wasn't destined to go to Bisley.
Honestly though, my summer of training with the reserves probably exceeds any amount of fun I would have had in England. I enjoy shooting, but not at the devoted professional level that a lot fo the Bisley cadets do. I suppose in a way it's a good thing that one of them got to go in my place, else I'd have been cheating one of them who honestly wanted it more.