I saw the pinch trim cutter and thought I would post the other version , expand and trim setup .. as for which is best I think it depends on length ? It certainly involves 2 steps vs. only 1 .
By the way Richard Corbin made this one for his walnut hill press , assume he still does .
The only problems I ever had was getting it stuck once in awhile on the spring punch ,external punch after it inserts into the now formed jacket ,Attachment 222601Attachment 222602Attachment 222603 if not adjusted correctly .