He hunts any cover and is steady to game and when birds are shot, but he has one annoying habit: when he brings in and delivers a bird, he jumps up to try to snatch it again.
I put my hand out to stop him, but this has no effect. What can I do?
During training, a controlled delivery should have been well practiced with dummies and then cold game, and presumably that part of his training was fully completed before he was worked on freshly shot game.
Going back to the training environment and working on delivery under ideal conditions might cure the problem.
However, there are certain things that can be done to discourage jumping up while he is in the shooting field.
You must not take game from him too soon.
Let him come in, and give lots of praise while he is holding the retrieve before you reach for the bird.
Do not snatch or pull it from him, but wait until he relaxes, and a gentle delivery should follow.
Finally, make sure you have a gamebag or a waistcoat with a large rear pocket and as soon as you have the bird, slip it quickly out of sight and then move to distract the dog to get him focused on something else, such as another bird, the command to start hunting again or a tasty treat.
Repetition will quickly see improvement.