In ohio you can use a high-powered rifle or whatever to kill deer with. The reason is that there is not going to be a couple hundred thousand hunters out with a high-powered rifle at once. Kinda the same reason you can use them on groundhogs, coyotes, etc. Now one thing that I would be questioning is the spotlighting. You used to be able to shine but I know that this year my permit was a no go on shining and everyone else I talked to wasn't allowed either. The limit on my permit is 5 people and 5 deer are allowed on each permit giving so a total of 25 deer. As far as diminishing the herd goes...it depends really. If there is a serious problem it will only control them at best. The property I got access to this year actually took 20 deer off of it during gun season and not with permits, they just had that many people throughout the week and the day after gun season they saw 16 deer out in the cut corn feeding at once.