Tune_up
Member
I was recently offered a good deal on a .280 so I bought it. Comparing it to my .270 they appear very similar ballistically. But reloading data consistently shows lower maximum pressure for the 280. On Hodgdons web site the powder/loads for a 140 grain bullet show pressures in the range of 49,800-51,000 CUP for the 270, and only 47,000-48,500 CUP for the 280. They are consistently lower comparing same powder loads between cartridges. If case volume and bullet weight are the same (some information shows the case volume of the 280 to be slightly larger and others show the 270 to be the largest, I intend on measuring myself) why would maximum pressures be that different? I am not interested in pushing beyond the maximum loads but I am curious.