I remember when I was in my teens, I got involved in NRA youth target shooting. We used an old, heavy single shot bolt action target rifles with peep sights. You would have to break your position after every shot to reload. Not exactly inducive to good accuracy. I still managed to qualify as expert. How much easier would it have been with a Fortner action rifle I'll never know, but the urge to try a Fortner biathlon rifle out for target and long range shooting is strong. Only problems are, I'm too darn old and don't have the $$$.
I also have to agree with MRBORLAND that a heavier rifle is easier to shoot offhand.
I can also admit that there are a bunch of rifles out there that are shooters. The thing is, I don't see any of them being used in biathlon competition. The standard bolt action is slower than a straight pull and is more disruptive to your shooting. The only movement in a Fortner is the index finger and the thumb.
The only person that I could see using a standard bolt action in this competition would be a wild boar hunter by the name of Franz Albrecht. I posted a video of him in the general discussion forum. He can work a standard bolt action almost as fast as he can a straight pull bolt. He is so fast, smooth and accurate, it's almost scary.