You're getting some pretty good advice above.I got what your saying, and sure hope to not ever have the need to shoot in anything in excess of 80 deg. For the most part I do most all of my load development and range verification between at no more than 50 deg. and try to keep it around 30 so things are as close to a day of typical hunting as possible. I really don't care to have two separate loads for different temps if it comes to that I'll just run Retumbo and live with 100fps less velocity.
Use the right powder with light bullets and it's not a problem. Lighter bullets, faster powders, Heavier, particularly at the high end of weight for a given caliber use slower powders and you can get great results.Yeah 195's or maybe a 180 grain for me in the 28 Nosler as mine is being throated for the 195. Anything lighter with a properly thought out over-bore gun is a waist of chaimbering and un-burnt powder if you ask me. Never could understand why people would insist on getting the hottest cartridge and want to shoot little lightweight bullets. Like a 300 ultra mag running 150 grain bullets or 40 grain bullets out of a 220 swift. I'm hoping that when my 28 gets done that I can find a good wide band for an accuracy node and like said load things on the bottom end of the node so as to give me safe loads in a wide range. If a different set of data needs to be ran on my Sig 2400 so be it. Or start using up all this Retumbo.