Would you do any load development in winter in northern WI ?

[VASCAR2]

It would make an interesting experiment to develop a load at lower temperature with chronograph results then shoot the same load at different temperatures. Keep a record of accuracy and velocity change for temperature change. From everything I?ve read IMR8208XBR is one of the more temperature stable powders used in the 6.5 Grendel. You have to use caution with 8208 as it will spike in pressure especially with bullets heavier than 120 grains. I?ve read the absolute max pressure with 120-123 grain cup and core bullets is around 28.5 grains. The monolithic bullets tend to build pressures quicker than cup and core bullets of the same weight so it is wise to start low and work up in .3 grain increments.

I wouldn?t develop a load at zero degrees with 28.5 grains of IMR8208XBR and 123 grain SST and assume it would be safe at 100 degrees. I would be interested in seeing any results if you choose to record your findings at different temperatures. I read velocity change might be less than 1 FPS per every degree of of temperature change with 8208. I read where CFE223 will change at least 1-1.5 FPS for every degree of temperature change.

There was one member from Alaska that did some velocity test at lower temperatures with the 6.5 Grendel but I don?t think he used IMR8208XBR powder in his test.

Here is a thread with info which might prove helpful.



http://www.65grendel.com/forum/showthrea...ensitivity