Re: brass and pressure question?
I have found that wby brass in general is greater in volume than other makes of brass for the wby cartridges. The wby brass can be loaded with a heavier powder charge where as the other brand of brass will reach those same pressures/velocity with a lesser charge of powder. Try running full tilt 257 wby charges in some converted w-w 7mm mag brass that's been fireformed. normally can reach the velocity with at least 2 grains less powder in the W-W brass compared to the wby brass.