Someone correct me if I'm wrong here; but is not the Giraud trimmer set up / designed to trim bottleneck type cases only?. I have a Giraud (& LOVE it) & the case holders are adjusted to headspace off the shoulder of the case to set your trim length. I do not see case holders for straightwall cases on Girauds' website??
Just a thought if USMC87 was looking to trim straightwalls...................