Do you have any problem with the barrel heating up and throwing flyers after 4 or 5 shots ?
Wow! Old thread. To answer your question about the 4th shot being a flyer . . . yes. My Tikka T3 in .223 was doing the same thing. Finally discovered that it wasn't due to the barrel getting hot. Are you feeding rounds individually, or loading up the magazine? I always leave at least one round in the magazine because the last one is always a flyer. Even though it has a light barrel, I can put 20 rounds through it (F-class style) in cool weather with little change in consistency as long as I don't empty the magazine. The OP actually showed the best solution using the "Bobsled". I'm going to get one too.