Reloading .303 British : Velocity change due to Ambient temperature.

^^^This^^^

My hunting buddies and I always worked up the most accurate handloads for our hunting rifles.  Said handloads were developed near sea level at ranges in and around Vancouver, B.C.  A couple of our favorite hunting areas were in the Shulaps/Camelsfoot mountain ranges (8,000 to 9,000 ft. asl) and the peaks above the Flathead Valley in the Rockies.  Hunting above the tree line necessitates long shots as crossing scree slopes can't be done quietly so before you emerged from the scant cover offered by low lying Juniper bushes we'd glass across the slopes.  We learned to compensate for a higher POI after the first Mule deer buck I shot had its spine blown out despite my aiming much lower.  The deer was dead before it hit the ground but it could have just as easily been a miss.