I'm looking to build a rifle around ammo that's available on the shelf (180gr & 200gr loads). What's a short barrel length I can get away with and what twist? Looking to shoot 1000yds(that's furthest I can shoot back home in NC, though I'm in CO right now). Only similar build I can find was here: http://huntbackcountry.com/300wsm-cut-to-185-inches where they loss 75fps going from 24" to 18.7" w/ Federal 180gr Trohpy Bonded Tips. Would there be any improvement in going with a faster twist than factory with a short barrel? The rifle will be suppressed next year when I go back home. TIA!