I have had the same experience you had but through a 637. I only fired three of them for fear either my hand or the cylinder might blow out. They are reserved for my 640 now as .357 seems a bit much but the Buffalo Bore is just right. I thought about pulling a bullet, but am not familiar with powders at a glance. That just isn't something I would want to "eye ball" test. To my eye Unique looks just less dull and a little darker than HP-38. That's not enough for me to say one over the other though.