my 5 week old doesn't wind? help?

My 5 week old is such a good baby, I'm really blessed with him. The last week however I've had serious trouble trying to wind him! I would always wind him every ounce, but now he cries if I try to wind him before 2 ounces, and 80 percent of the time I can't get any wind up! He drinks 5oz per feed, and I might get one burp up half way through and that's all... he doesn't seem like he has any wind anymore! He never acts in pain! Is he just not getting any wind anymore? I could spend the guts of an hour trying to burp him after a bottle and nothing.... he would even have say 3oz before bed, fall asleep and I could spend an hour trying to burp him, and then eventually lay him down just to see can I bring the burp up.. but he won't bring his legs up or act in pain he'll just stay asleep. He has very good control of his neck.. could this have reduced his gas? It's stressing me out that all of a sudden he doesn't wind, I mean because he doesn't seem stressed I normally give up after 40 minutes and then try Again after awhile, but I never get anything up?!