YES. You should be wary. Revolvers are finely tuned mechanisms that can become worn by misuse, improper care and accident. As much as I consider myself an afficionado of the revolver, I too have wanted a gun so badly that I've ignored the most common and logical 'checklist' for making a used purchase. First off, is the seller the original owner? Ask as many questions as you want. Ask for photos. Specifically ask to see the barrel face (forcing cone) area and look for scoring that will tell you if the cylinder and crane are aligned and how much use the gun has seen. Remember that with the heavier calibres it IS normal to see SOME flame scoring on the barrel face. This usually progresses to a point and then with heating and cooling, the barrel face gets hardened and it stops. A barrel face that shows 'scars' from the inside diameter all the way to the outside diameter is NOT GOOD. Another thing to look out for is heavy flame scoring around the cylinder face where the chambers line up with the barrel face. Any scoring around the chambers here means the gun has seen ALOT of rounds. Another give away as to amount of use is top-strap cutting. This is when the area of the top of the frame (above the cylinder right where the cylinder face meets the barrel face/forcing cone) where the hot gasses spray from the gap and erode the metal of the upper part of the frame. cutting is normal but look at photos online to get an idea of how much is too much! Next comes the obvious, a drag line around the cylinder and play when locked up. Most revolvers that have been used at all will have some form of drag line. The thing to watch out for is any wear on the little notches on the cylinder. These little halfmoon indented notches are what lock and align your cylinder. Any wear or sign of rounded edges on these is BAD. They should be sharp and well defined just like the bolt. HA! yes, it's called a bolt! (often referred to as the cylinder lock) The little tab that juts up from the bottom inside of the opening in the frame. You know, that litle tab that pops up and slots into the indentations in the cylinder. That litle bugger should have nice sharp edges to lock itghtly into the matching cylinder grooves. The movement of the cylinder back and forth on the gun when locked up. I say 'when locked up' because that's when it really matters. Another sign to look for wear is rounded edges on the cylinder pawl. That's the little circular notched thingy that you see when you open the cylinder. those little notches around the centre pin are what the 'hand engages to turn the cylinder when cocking. These should look like sharp little wedges. Next is cylinder 'play'.If a cylinder is a tad sloppy back and forth when open....no big deal. If a cylinder moves 1/16th of an inch back and forth when locked.....POSSIBLE ISSUE. Now, some of what I've stated here is only assessable by hands on demonstration (or an honest seller!), so most of the detective work for an online purchase will rely on photos. As far as I'm concerned any person selling a gun should be ready to supply any photos requested by a serious buyer. Without photos, walk away, and with that said go online and do your homework. Look up 'forcing cone erosion' and 'cylinder play', learn to identify what a bad purchase looks like BEFORE YOU MAKE ONE. Cheers