how old do u cull pups?

I know this can open up a whole new can of worms, but I have seen some dogs do nothing for one owner only to become the best dog in the pack for another. I wonder if you really like the dog but think he might be a cull, maybe send him to a trustworthy buddy to hunt with and see if he turns on. Perhaps he could get his confidence with the buddy (or the buddy's dogs) and then see if he would end up working for you. If he doesn't work for either of you, odds are he really is a cull. He had his chance to turn on as a hunting dog and so needs a different job on someone else's feed bill.

Cheers
M