"...what is the largest caliber..." Depends on where you're hiking/camping. There are several municipalities, names are on page 71 of the hunting regs under Small Game, that say nothing greater than .275 calibre, by the cartridge name, not the actual bullet diameter. A .270 Win is ok, but a .280 Remington is not. Some say nothing greater than .270 for anything. Those are mostly around TO. Means a .275 Weatherby is out despite both using the same bullet.
"...What is crown land?..." Land owned by the Provincial or Federal government that is NOT leased to a mining or logging company or used as a Provincial or National Park. Free access to anybody, including the assorted riff-raff. Cross country Skiers, hikers, picnickers, etc.
"...do you have the actual section for this?..." There is no law. MNR policy only. Section 109 of the Fish and Wildlife Conservation Act sort of covers it though.
http://www.e-laws.gov.on.ca/html/sta...41_e.htm#BK123
A shotgun in a duffle bag won't be of much use if Yogi (more likely to be Cindy with cubs) takes exception to you being there. You'll never be fast enough.
"...on my quad..." Having a loaded firearm in or on ANY vehicle is illegal.