Velocity change due to Ambient temperature.

Good Double Base Powder ………….. 1.0 fps per deg F

Average Single Base Powder ……….  0.3 - 0.5 fps per deg F

Best Single Base Powders ……………. 0.1 - 0.2 fps per deg F

Don’t know what “average” double base powders do, but presumably over 1 fps per deg F.

I will use these loads in February for an ISR event, that is being shot on reduced targets at 200m. This is st the Napoleonic indoor range, where we have our normal TAR ( Tir Armes Reglementaire) Service Rifle competition. Which is four weeks later. So I am using the ISR match as a practice match. I always have issues at this range, because the light is very different. The roof is partly open to slow the light in, and shadows on the targets.  My spotting scope is ok on the outdoor range, but I can never see anything in the black at this range.

I have a better scope on the way, so will be testing that as well.

In the TAR competition, we can only use the scope during the 5 test shots. Not during the match shots, until the round is finished.

I'll let you know how I get on. 

^^^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.