There are no "specs" since everyone does it their own way.
Some "specs" if you will:

The ejector IS NOT chamfered.
This really isn't possible without possibly damaging the ratchet area. Chamfering the ejector has no effect on faster reloads, since the only area that really needs to be beveled is the outer arc of the chamber mouth.
Take the ejector OUT before chamfering.

Chamfer only enough to break the sharp edge.
Going deeper really does little good, and may ruin the cylinder and allow swelled or even burst cartridges if enough support is cut away.

Advantages are a slightly faster reload with speed loaders.
Disadvantages are extraction problems or burst cases if too much is done.

Note that too many go too deep the first couple of times they do it. More is not better.
Again, all that's needed is to just break the sharp chamber mouths.