I picked up a XS7 .243 this spring. The 85gr Sierra BTHP's have shot the best out of it followed by 70gr. NBT. I have decided to use the 85's for this season, so I have yet to see the performance end of the bullet at work. At the range the 85's over 38 gr. and 39 gr. RE15 is averaging 0.6" 3 shot groups at 100. My old Hodgdon manual shows the 38 gr. as max and m.v. of 3176. I am guessing less w/ 22" barrel and will chrono in mid-September. The lowest charge shown w/ RE 15 is 35 gr. at 2896. I am probably more recoil tolerant, but at 38 they don't have much kick in the XS7 to me. I bet a mid-load w/ RE15 would be a great starting point. The 85's have to be seated deeper than NBT's or E-tips so the bolt will close. My OACL with 85's is 2.655". I can pass along data for the 85's with other powders, the 90 gr. e-tips, and 70 & 80 NBT's if you decide to try them.
