The PCR proposal will allow:
Straight-walled cartridges which are currently legal in handguns. Ohio deer hunters have used handguns with these cartridges for decades without incident. These are the only cartridges which will become legal in rifles. The ODNR Division of Wildlife maintains a more complete list.
The 3-shot plugging rule is required for the pistol caliber rifles (PCR) the same as for shotguns.
The PCR will only be allowed during any deer season which currently allows the use of shotguns and handguns. Basically these seasons are the early youth deer gun season and the traditional deer gun week which opens on the Monday after Thanksgiving.
This type of firearm is lighter than shotguns and muzzleloaders, making it ideal for youth, the physically impaired, or any hunter who wishes to carry less weight.
The pistol cartridges are actually less powerful than the newer shotguns with rifled barrels, inline muzzleloaders, and sabot bullet technology. There is less recoil than with 12-gauge shotguns again making them ideal for smaller hunters.
Because it is a rifle with a shoulder stock, it is easier to shoot more accurately than handguns.
All states adjacent to Ohio allow PCR hunting for deer. Indiana moved to allow PCR for deer several years ago with no reported problems.
From what I'm reading, Ohio will be a bit different than Indiana. Whatever has been legal in a pistol in Ohio will be allowed in a rifle. 44 Mag, 357 Mag, 45 LC , 45-70 and other chamberings will be allowed.