My apologies to the dead horse, but I'm still curious about the recoil thing.
A little while back we discussed internal ballistics a little bit, particularly the relation of case shape to the "Bill Lear effect", and in turn its relation to recoil. I think we concluded that two major factors that are difficult to really figure for are case length and shoulder angle. However, as was mentioned, short cases have to have sharp shoulders. The only way to avoid the shoulder is to lengthen the case and taper it like the H&H.
So here's my question- since we have to choose between short case and no shoulder, which do you think is the bigger contributer to the "bill lear effect"? Could you knock off more of that jet effect by shortening the case and leaving a sharp shoulder, or by lengthening the case and just tapering it?
Even though I've really liked the short-mag concept, I almost wonder if its purpose is defeated by the necessary shoulder, and if the longer case is worth it for the sake of achieving an H&H-like taper.