the temp sensitivity of the powder could affect the powder performance. If you had a velocity for your loads at 70-80 degrees you could then compare your velocity at 40-50 degrees, then have a better idea what is going on.
used to clean every 500 rnds... then a highly respected f-class shooter asked me if I wash my ass after I shit... now I clean the barrel after each match and/or practice round. I do use a 22 cal jag in my 6mm bore so its not super tight. Just push 3-5 soaked patches through and let sit for an...