That gun in the photo is a rifle. Bolted hammers on rifles with non-rebounding locks were common. Not on shotguns.

Rocketman is right so I won't repeat all he posted. Basically hammer guns have two safeties- a third one like that employed on the new Purdey hammer guns is in my opinion un-necessary.

Hammer guns are not fro everybody. If you get used to them and their peculiarities, they are fantastic. If not, stick to what you are comfortable with and competent at handling.

www.vintageguns.co.uk