RE: Gun question for deer
You can, but they are not very accurate in my opinion. You are shooting a gun that does not have the barrel fixed to the reciever, mounting a scope to the reciever will not give you the most consistant mounting configuration. It may work alright until you take the barrel off to clean it or swap it out for something else.
If you are shooting rifled slugs out of a smooth bore I wouldn't even bother with a scope, just get some clamp on adjustable fiber optic sights. You probably won't get the range out of a smoothbore to warrant a scope anyway.
If you are going to use a rifled barrel and want to use a scope try and get one with a cantilever mount if you can, it will be more accurate and versatile in the long run.
Paul