Ok I'm a varmint shooter so I'm whacking chucks at 90 degrees F and other critters usually around 20 degrees F sometimes lower, rarely below 5 degrees F. I read about temperature sensitivity all the time but never in a satisfactory way about the parameters of the testing used to make the determination.
My school of thought for my ranges, 600- yards with my 6MM Remington and 350 yards with my 223 with 75 grain and 40 grain projectiles respectively that hyper velocities (high pressures) reduce time in flight and flatten trajectories at the ranges mentioned making hits more feasible. These loads are near max a 65,000 PSI for my 6MM and 63,000 for my 223 so there's no headroom for increased pressure in heat.
I work loads in summer heat, when I find a keeper I test 20 or so by letting them sit on the bench in the sun until evenly browned, uncomfortably hot to the touch. I shoot, clock and zero at 3" high at 300 yards for the 6MM and on at 300 for the 223. I reduce the load if pressure signs appear and do it again if needed.
When I shoot at 20 degrees F with the same load in the winter I don't change my hold. This is a basic safe to shoot anywhere test.
In my opinion to make a test that has reasonable validity one would need a single load of 100 rounds, shoot 50, clocked, grouped and pressure tested after being subjected to the high heat for 24 hours. Then repeat the process at the low temperature. If you're mapping several temperatures this needs repeated for each temperature, for powder choices also. I can say from over 50 years in the field as long as my summer load is not too hot all is well.
Except for ball powder in my 30 Carbine high pressures not the issue, ignition and cycling is, magnum primerscsolve this.
My school of thought for my ranges, 600- yards with my 6MM Remington and 350 yards with my 223 with 75 grain and 40 grain projectiles respectively that hyper velocities (high pressures) reduce time in flight and flatten trajectories at the ranges mentioned making hits more feasible. These loads are near max a 65,000 PSI for my 6MM and 63,000 for my 223 so there's no headroom for increased pressure in heat.
I work loads in summer heat, when I find a keeper I test 20 or so by letting them sit on the bench in the sun until evenly browned, uncomfortably hot to the touch. I shoot, clock and zero at 3" high at 300 yards for the 6MM and on at 300 for the 223. I reduce the load if pressure signs appear and do it again if needed.
When I shoot at 20 degrees F with the same load in the winter I don't change my hold. This is a basic safe to shoot anywhere test.
In my opinion to make a test that has reasonable validity one would need a single load of 100 rounds, shoot 50, clocked, grouped and pressure tested after being subjected to the high heat for 24 hours. Then repeat the process at the low temperature. If you're mapping several temperatures this needs repeated for each temperature, for powder choices also. I can say from over 50 years in the field as long as my summer load is not too hot all is well.
Except for ball powder in my 30 Carbine high pressures not the issue, ignition and cycling is, magnum primerscsolve this.