checking for cracks

what can you due to check for cracks in a revolver cylinder  with out damage to the finish can magnetic particle  inspect detect ?

between two chambers in the thin web look like might be a crack.

Kroil, if there is a crack it would make it through. And wouldn't hurt anything to sit in in a cylinder for awhile. Air could also work.

Yes, Kroil is a good way.  Saturate the surface with Kroil, wait a few minutes and then wipe it all off.  Let the piece sit for a while and then inspect to see if there is any Kroil on the surface. It usually makes a line following the crack.  Especially useful for checking Hammerli and High Standard frames and .22 conversion slides.

The cylinder should be viable for MPI - provided it's ferromagnetic. Most will be, but some 'stainless' compositions aren't, and I'm not sure whether any are used for revolvers. 

But Kroil's going to be a lot easier unless you've got a MPI unit handy and know how to use it. 

If so, you can detect sub-surface fissures w/ MPI as well - so potentially stress fractures that are emerging.

Degrease.   Spray with dry white powder spray (like an athlete’s foot spray). Put Kroil on qtip and put it on one side of the suspected crack.  If it is a crack, the oil will wick through and turn the white on the other side dark.

If you have an automotive machine shop near by, particularly if they grind crankshafts, they would probably magnaflux the cylinder for you for a nominal fee. There would be no damage to the finish.

I can do it but you'd have to ship it

thanks for the tips on Kroil and how to use it I will try  that and see if I can see any thing if not will keep shooting it