An example from the Milt Sparks line. I got a PMK for a 3" N frame for a woods gun. After a quick break-in period, to test the holster's holding ability of the gun, I held the holster with gun upside down over my bed (unloaded gun) and shook it repeatedly up and down. The gun didn't move any.
If you decide to order a Sparks but don't want to long wait, try here:
http://www.lightningarms.com/ I've dealt with them a couple of times and have yet to hear of someone having poor service from them.
Another site to order good holsters from (not as nice as Sparks but still good) is
http://www.gunnersalley.com/ Once again, I've dealt with them and had good service from them. They do have a good return policy and I have used it (a holster that just didn't fit my body).
Steelheart