Never had to trim first.
I bought some PPU in desperation that has not been used and it went fine as is. I have a batch of 100 Starline (dwindling) that I've been using all summer and they formed fine without trimming first also.
I now have a fresh batch of 200 Starline and the only thing I did different was to anneal them first, because for whatever reason the shoulders on my first batch got very hard, which I noticed during processing after the first firing.
IDK why, just happened.
I bought some PPU in desperation that has not been used and it went fine as is. I have a batch of 100 Starline (dwindling) that I've been using all summer and they formed fine without trimming first also.
I now have a fresh batch of 200 Starline and the only thing I did different was to anneal them first, because for whatever reason the shoulders on my first batch got very hard, which I noticed during processing after the first firing.
IDK why, just happened.
SI VIS PACEM, PARA BELLUM