I don't own a 204 and would not use it on a regular basis for deer size game if I did. I am simply saying from experience that small calibers under the correct conditions and with proper shot placement will cleanly kill deer. I have no reason to continue said named activities with a .17. All that said there are a few state sponsored groups that kill deer on public golf courses and in populated areas using a .22 LR supressed rifle shooting 60 grain Sub-Sonic rounds. They have been doing this for quite a while and have found it to be effective. Again this is not something for your average Joe to try, these are well trained marksman.