I’m looking for some advice. I am working on my first ever handload. Its for a 338 win mag. I loaded up my first batch of test rounds and they chambered with no problems at home, a couple weeks ago. I went to the range this morning and none of them will chamber, they are all too tight. Factory rounds will chamber with no problem. I worked up some dummy rounds, increasing the seating depth by a large margin and bumping the shoulder all the way out to match the factory rounds - still won’t chamber. The only difference I could find between mine and the factory rounds was the diameter at the base just above the belt is running about 5 thousandths. Could that be it? If so, what can I do about it? I assume the Florida heat and humidity is the reason for the difference from when I loaded them until today, but surely a full length sizing die works in the summertime too, right?