If you have given him a lot of chances (and only know what a lot of chances is), you will know when the time is right. I dont always believe in keep feeding tracks. I've been at this a while and seen dogs under a year that hunt and dont come back. I now have a certain standard and if the dog is not at that standard, they dont stay. You have to deveop your own standard and answer your own question. I asked the same question you did many years ago.
X2..lots of good advice but at some point you have to decide...I don't give many chances...I like pups that are born to hunt...