Originally Posted by hogship
If you pull the hammer back very slowly, make sure the cylinder locks up BEFORE the hammer does, on EVERY chamber. If it doesn't, you are relying on cylinder inertia to do this, and it's something that could be dangerous, under the wrong conditions. This should be under the "timing" category.
This is checking carry-up. On later Smiths, without the pair of locating holes in the ejector star and corresponding pins in the cylinder, carry-up is checked with snap caps or SPENT cases in the charge holes. There is too much free play in the ejector to achieve reliable results without.