Wondering if everyone is taking a couple shots of cheap ammo to warm up the barrel before testing different loads for accuracy. It seems that once the barrel gets warm tot he touch, my groups tighten up and I want to test the loads for accuracy, not the barrel and not me. I was thinking of taking 3 shots with garbage rounds (inaccurate loads rather than pulling the bullets, use them for warming up) before trying new accuracy loads. I would hate to discount what might be the most accurate recipe because I was shooting a cold barrel and an open group. Or is it even worth the trouble for the amount of difference?