If you choose Smith & Wesson, the main things to look for are:
Overall appearance- does it look like some one cared for it?
Cylinder play- With the hammer at rest, move the cylinder front to back. A SMALL amount of movement is normal. If you have a more pronounced "click clack" you have a condition known as "end shake cylinder". This is not a fatal flaw. It can be corrected fairly easily but it is a good indication the gun has been fired quite a lot with magnum or higher pressure ammo. You should not ever see this on an L-frame revolver (581, 586, 681, 686) They are built dead tough and will last a lifetime.
Flame cutting on top strap. Open the cylinder and look at the top of the frame immediately above the back of the barrel (just above the gap between the cylinder and the barrel). On the K-frames (19, 66 etc) a small groove is normal. It should not be deeper than about 1/32 of an inch. If the groove is more pronounced, the top strap of the frame has been weakened by A LOT of magnum ammo. This will give you a pretty good idea how abused the gun was. The L-frames and N-frames should not have this condition as there is more space between the cylinder gap and the top strap.
If someone tells you a Smith should not have a "ring" around the cylinder at the stop notches, They have no clue what they are talking about. A properly timed Smith will have a slight "ring" around the cylinder where the cylinder stop "just" touches the cylinder as it rotates.
Overall appearance- does it look like some one cared for it?
Cylinder play- With the hammer at rest, move the cylinder front to back. A SMALL amount of movement is normal. If you have a more pronounced "click clack" you have a condition known as "end shake cylinder". This is not a fatal flaw. It can be corrected fairly easily but it is a good indication the gun has been fired quite a lot with magnum or higher pressure ammo. You should not ever see this on an L-frame revolver (581, 586, 681, 686) They are built dead tough and will last a lifetime.
Flame cutting on top strap. Open the cylinder and look at the top of the frame immediately above the back of the barrel (just above the gap between the cylinder and the barrel). On the K-frames (19, 66 etc) a small groove is normal. It should not be deeper than about 1/32 of an inch. If the groove is more pronounced, the top strap of the frame has been weakened by A LOT of magnum ammo. This will give you a pretty good idea how abused the gun was. The L-frames and N-frames should not have this condition as there is more space between the cylinder gap and the top strap.
If someone tells you a Smith should not have a "ring" around the cylinder at the stop notches, They have no clue what they are talking about. A properly timed Smith will have a slight "ring" around the cylinder where the cylinder stop "just" touches the cylinder as it rotates.