As long as you keep a shell in the adapter, ready to go, and the adapter handy, I don't see what the fuss is about. My primary concern with a coup de gras is to finish off the animal as quickly and painlessly as possible. Fumbling around with an adapter isn't an option, but if it's quick to deploy, then go for it. I wouldn't #### around with low power loads, I'd want something that easily goes through the skull. I do recall ROss Seyfried writing about trying to finish off an elk with a 38 and self defense hollowpoints- the bullets weren't penetrating the skull much, form point blank range.