Been reloading for close to 25 years and I may just be having a senior moment, by why would this batch of .223 cartridges vary by .010? I am using the same lot of Speer FMJ bullets and the brass is FC trimmed to 1.750. I've had some other reloads vary slightly, but never noticed any this bad. I set up the seating die to seat the first bullet in the center of the cannelure with no crimp. The first 4 were spot on, then I noticed that the 5th bullet was seated below the cannelure. Am I missing something?