I got this H&R when my Dad passed and he acquired them not too long before. As far as I know Dad never fired it and I would like to Know exactly what it is and what type of Ammo to use in it. I'm pretty sure it's 38 S&W but Not sure if I can use modern ammo or not as the caliber is not anywhere on the gun. SN=49376 under the top strap, and on the heel of the grip, also notice the last 3 digits are on the back surface of the cylindar and on the ejector. It has MOP grips and looks as though it has been shot very little and kept very nice for as old as I think it may be. Any info would be greatly appreciated. Thanks in advance.