I'm loading some .38 sp and getting huge variation in power. I am using home cast 158gr bullets with vectan A1 powder.
With 4.5 grain I am getting 122- 230 ft/lb, so I upped it to 5gr and am getting 166 - 280.
I am using a LMBR chrono in the cellar, could this be a lighting/smoke issue? I can't use the pistol in the garden and was loading some up for the range tomorrow. Should I just retest in daylight then, or could it be something else?