I just bought my first decent (I hope) airgun, a Gamo swarm fusion gen2 to be delivered in a couple of days. From browsing around I read that the included scope is not that great. I have a Leupold 2x7 scope I used to have on my old squirrel hunting 22. If I don't like the scope that comes with the airgun can I put the leupold on it? Does a scope for an airgun have to be specially made for them? Thanks