The Webley does have some "slop" or play in the frame and cylinder. But cock it, ease the hammer forward, while keeping the trigger depressed, and you'll see that the cylinder and the frame lock up very nicely. Or they should if everything is working properly. to the best of my knowledge the measurements are within normal range.

I've read that the slop was intentional. It was a revolver meant for hard field use by officers and sportsmen who were frequently hundreds of miles from the nearest gunshop. Like the AK-47 it has alot of empty space and large tolerances to take into account mud, dirt, gravel etc. Supposedly the MK V and VI kept functioning in the mud of the Western Front during WWI while the Smith and Wesson Triple Lock in .455 was too tight and didn't do as well. Which was one of the reasons why S&W got rid of the cylinder rod lock.

Make sure the screws aren't buggered and that they are tight. Sometimes it isn't unusual for the screws to be stripped. If they're loose and won't tighten that could be a bad thing. It might mean the screws are no good or it could mean something worse. Check for bulging in the barrel, look over the rifling in the barrel, remove the grips and look for excessive corrosion etc. Make sure it funtions properly, the barrel tips forward without having to use force and when cocked the hammer can't be pushed forward. That is a very bad thing indeed.

Also whne tipped forward the ejector should have some real power to it. If it's sluggish or weak then something is wrong with the spring and you might not want it. Ensure that the frame stirrup (or lock) locks the frame into place as well.

Okay that's all I can think of for now. Hopefully that gives you a start.

I'm a huge fan of the Webley revolver. Also here is another website that is an exceptional source for all Britsh military firearms.

http://forums.gunboards.com/index.php