I'm this close to having a rifle rebarreled to 257 Wby for use as an open field deer rifle. The 257 is tempting, but I'm wondering how many rounds I can expect out of a 257 barrel with 100 "X"s clocking 3700 fps. For those on the board with 257s, how many rounds have you put through these barrels, and what are your experiences re accuracy fall-off and throat wear? Thanks.