If he is new to the sport he is going to need some grooming. I would clean the entire rifle with him and explain to him that to verify the accuracy of your load depends on a clean property functioning rifle. It will definitely help you on a load work up. As for me I have three Browning's the hunter 300 WM, Hells Canyon 300 WM with cerakoted bolt, and the X-bolt pro long range 7mm RM coated as well all the actions are glass. He may simply not know gun maintenance. Explain to him when to clean as well. He obviously trusts your knowledge. Coach him up and he will stay in the game, after all we are all a family of shooters sharing knowledge with each other. Be positive and supportive. The US Army taught me and I taught others in Sand Hill down in Fort Benning Ga.
Which round are you working up?