In my experience, you can get a lot more loadings on a 223 and 243 case than the numbers you mention.
For one thing, in general I don't think you should ever shoot a load in the summer that was a max load in the winter. Hodgdon extruded powders may be the exception to this, but you'd be much safer working up the load again when it gets hot. Even the Hodgdon powders show some temp sensitivity.
Another thing you mentioned is your reloading routine. I was just telling this to a guy at work today, I NEVER seat primers in cases unless I am ready to charge with powder and seat a bullet right then. It's just too easy to put a different primer in that case and then forget what you did or why you did it the next session. What you're doing is worse than a simple distraction.
