Ok here I am loading up a bunch of mixed brass 30 carbine, all once fired by me. Head stamps, FC, WW, R-P PPU and PMC.  The gist of this is that I'm reloading for about 25% the cost of new cartridges, for a fun carbine keeping 200 yard prone hits on 9" paper plates, most in the 6" center, having fun with my children and grandchildren, not winning bench rest matches.

I measured up a handful of each type and while none were too long they varied too much to make seating, removing the bell for reliable functionality possible, in my opinion.

Now here's the process, after measuring 30 of the unsized cases I picked the shortest to trim to. That was 1.266" which is .014" under minimum. Out of 387 cases about 10% of all but one type would not completely true up at that length, it was 20% of the other type. Meaning that the trimmed edge of those were not completely cleaned up. I use an RCBS Pro Trim which I like it only runs about 80 RPM and the case length variations are very small.

I use a carbide die set by RCBS, I keep my hands gooey with Unique case lube anyway. After sizing they measured 1.280 to 1.28, I kept the one that couldn't be trued up separate but I'll load them anyway.

I guess they all cut them as short as possible to save money!