ORIGINAL: HEAD0001
The jump to the lands is why I believe the large for caliber bullets shoot better(less jump). I have experienced this in a half dozen different Weatherby's that I own or have owned. As far as the pressure is concerned I am puzzled by the comment of greater velocity without greater pressure. First I was under the impression that Weatherby caliber's operate under greater pressure to achieve the higher velocity. Second I have been under the impression that the freebore causes higher pressure? I am not questioning the preceding poster, only that I have had Weatherby representatives at the shot show say the exact same things that I said. The preceding poster could be correct, but I do not see how you could get greater velocity without more pressure? Tom.
First, one has to understand average pressure, and peak pressure. Think of it as a pressure curve with pressure on the y-axis, and barrel length on x. The limit for pressure is the action/barrel combo. Usally set by SAAMI. You can smooth out the pressure curve by letting the bullet get a running go so peak pressure is not so high. Freebore can come with a price of accuracy however. Think of trying to break down a door by pressing statically and then getting a running go.