BPI has sent load recipes to me when I asked via email. They may have some 2.5" recipes that they would email or FAX to you.
I have read that roll crimped loads tend to have lower pressures than similar fold crimped loads. In a paper hull the difference may be small. I think the overshot card pops out from under the roll easier than a fold crimp opens, especially for a plastic hull.
Ballistician Larry Nailon mentioned in an article that loads with some wads, such as the old Federal Champion and the Windjammer with staircase cage push the crimp open from the center, and show lower peak pressures compared with loads using wads that push the crimp open at the roll. I think the roll crimped load would open easily like the claim for Champion or Windjammer loads.
