Just from an engineering standpoint, let's examine the frame... the strongest design to resist linear forces of bolt thrust would be a bolt enclosing frame with 360 deg of radial support with a square bolt/frame abutment....but approximately 170 degrees of frame is missing between the 11 o'clock and 3 o'clock position. My theory is that at the moment of peak thrust the receiver flexes away from the 170 deg opening, perhaps violently (by engineering standards at least, you would need multiple strain gauges to record it). This, theoretically allows the inclined plane of the bolt/frame juncture to move from the 'at rest' mating, rear of the bolt perhaps going down the inclined plane and perhaps the frame flexing up and to the left (the rigid supported side). What happens at peak thrust with the cam that holds the bolt up on the inclined plane abutment is more conjecture (I don't have a 99 handy), but I guess there are working tolerances (slop) in the linkage and also the fact that the cam itself is not very robust, being an arc of maybe 3/16 thick ordnance steel? They are one of the most elegant sporting rifles ever built, I believe they are safe, but if I were an engineer I would call the design...adequate. I would have liked to be the fly on the wall at the meeting between engineering, sales and corporate when they decided to extend production to 60,000 psi cartridges.
