Right, 300 yards seems outside the normal, practical range for either chambering. My thought is/was within 150 yards, or so, there is no practical difference. I would think a regular need or interest in 300 yard capabilities would indicate some other chambering... although I'm no expert and I have no experience at 300 yards using either.
Gotta disagree in both cases.
First, 300 yards is easily within the capabilities of the .257, no doubt about it.
...
Exactly right. If the 125g Sierra at 2600fps is a 300 yard bullet, the .257 Roberts with a 110g AccuBond at 3163fps (+P pressures) is a 500 yard cartridge.
.30-30 @ 300yards w/ 125g Sierra and 2600fps MV = -25.8", 1065fps, 315fpe
.257 Roberts @ 500 yards w/ 110g AccuBond and 3163fpsMV = -29.3", 2133fps, 1111fpe
In fact, in terms of fps and fpe, the .257 Roberts with my 110g AccuBond load has more of each at 1000 yards (1352fps, 446fpe) than the 125g Sierra launched at 2600fps has at 300 yards.
