Lighter bullets equal higher velocities
Higher velocites burn larger charges of powder
Larger charges of powder increase both heat and physical erosion and blasting effect on the lands.
Slower burning powders sustain the heat.
If you spread the shots, the barrel will last several lifetimes even on a .257 Weatherby.
If you range shoot, it will be done in 800-1,000 rounds no matter what bullet weight and powder charge.
JW
