Increasing the case capacity of a 7x57 to that of a 280 does not yield as much MV increase as moving from a 308 case to a 30-06 case in a 30 caliber round. The expansion ratio just isn't as favorable.
Just for grins, we can compare the 7x57 shooting a 150 grain bullet at 2850 FPS to a 280 shooting the same bullet at 3000 FPS.
One way to set a maximum range is to compare the ranges at which the bullet drops 24". Past that, you have to be a very good range estimater to get your elevation right. At 2850 FPS, the 7x57 reaches this point at 415 yards. The 280 is good to 425. Advantage, 280 by 10 yards.
Another way to set a maximum range is to compare the distances at which the bullet drops below 2100 FPS. This is the range where conventional bullets stop opening reliably. For the 7x57, the range is 400 yards. For the 280, it's 465. Advantage 280, by 65 yards.
If you're using Partitions, the magic impact speed is 1700 FPS or more. 7x57, 635 yards, 280 715 yards. Advantage 280, by 80 yards.
There is another side to the speed argument: If you're shooting at 3000 FPS with standard bullets, you might want to consider whether you want to take shots within 100 yards. That's the distance where the bullet drops to 2800 FPS. Above that, standard bullets open too much and too quickly, producing shorter wound channels. For the 7x57, this distance is 25 yards. Advantage 7x57, by 75 yards. Of course, if you're shooting premium bullets, this probably won't be an issue.
If there is any great lesson from the 10,000 moose thread, it is that there are many combinations that work very well.
Understand what your favorite rifle and load will do, and enjoy using it within those limits. Barring unusual situations, the one and only purpose of a firearm is to bring enjoyment to its owner. If it does that, it's successful.
Last edited by denton; 12/30/07.
