had a 25-06, and a 270. A buddy convinced me to start reloading. bought Winchester brass for the 25-06 REM and Remington brass for the 270 WIN.

followed everyone's advice to run new brass through resizing die to true up mouth dents.
set up the 270 die per instructions. Lubed the 270 casings, went to work. Was excited about my success smoothing out all the neck dents.
Finished the 270's.
lubed all the 25-06. the first 25-06 casing was a lot harder to run through the dies. Stopped and googled "is Winchester brass harder than remington brass". found several posts that Remington tended to be softer, so ok, I continued with the 25-06 casings through the resizer. They were all noticeably harder to resize than the 270's, but afterward I was excited - I'm on my way.

primed all the casings the next day. I'm on my way

Next day, loaded 5 3 shot powder charges of imr 4831 in my 270 casings. Put the 270 seating die in and seated 15 150 partitions. I'm on my way.

next day, loaded 5 3 shot powder charges of Imr 4831 in my 25-06 casings. went to put a 110 grain accubond in the 25-06 Case mouth. It fell into the case until it hit powder.

i then realized that I had yet to open the 25-06 die box! The first day I had resized all my 25-06 brass with the 270 dies! No wonder that winchester brass seemed so hard?

Was so flustered. I'd ruined my brand new 25-06 brass. so I dumped the powder back in the bottle, and threw the brass away. Ordered some new brass

didnt tell my buddy, who had convinced me to start reloading, until about a month later. He said "don't worry about it, it didnt't hurt the brass to neck it back down." That was 5 years ago. To this day I've never told him I threw the brass away.