The following has been copied from a tip in the ballistic software Precision shooter workbench 4.. "In general, muzzle velocity will increase with increasing powder temperature and decrease as the powder temperature decreases. The "per degree" change of velocity depends upon a number of factors, the calculation of which is beyond the scope of this program and the user is advised to consult an internal ballistics program for this information. (The user is directed to the powder manufacturer for specific powder specifications. Alternatively, QuickLoad (tm), for example, can help the user make these determinations.) Suffice it to say that powders that are relatively temperature insensative may have muzzle velocity increases of only 1 fps per degree or so while other more sensative powders may have muzzle velocity changes of 2 or 3 fps (or more) per degree change. The user may experiment with his powder of choice."
My question is... somebody could you help me how I can find information about the performance of the powders ?
For example if my value is 775 m/s vith Vithavuori N550, 175 grains sierra match with 25 C°...... if I'll shot the same reload with a different temperature how is the change rate to put in the calculation to get the new muzzle velocity ?