Am getting back into loading metallics. With new Starline brass do I just prime, add powder & seat bullet? These will be light 41mag and 223 loads. No case prep required - case sizing, trimming, etc?

If I wanted to do the minimum, I'd at least run the rifle cases over an expander ball to round out the case mouths. Flaring the handgun brass prior to charging and seating should take care of dented case mouths for the handgun brass.

You might want to check for uniformity of length on the 41 mag brass.

A few years ago I ordered seven hundred pieces of 41 mag Starline brass.

I flared a bunch and loaded them, and crimped with a Lee factory crimp die. I noticed the crimps were not very uniform.

I found the shortest piece in the lot and trimmed them all to that length. I have been using that batch for about ten years now with around a dozen loads on some pieces.