|
Been doing some research on the 7x57. It's amazing how close it is to the 270 in some respects.
As nearly as I can figure out from known numbers, a 7x57, loaded to full modern pressures, will push a .284" 140 grain bullet to 2900 fps.
The SAAMI spec for a 270, loaded with a .277", 140 grain bullet is 2950 fps.
There's just .008" difference in diameter, and 50 fps difference in MV. Of course, as bullet weight goes up, I would expect the difference between the two to widen some, because the 270 has more case capacity. But, all in all, these are two very similar cartridges.
So why is it the 270 "caught on", while the 7x57 didn't?
|