You know, I thought long and hard about the Schofield break-tops.
Final analysis: forget it. There's a reason that design died out.
The Italian versions have labels all over 'em to the effect of "Cowboy loads ONLY". That means usually 230 - 250grainers doing less than 800fps, sometimes down near 650, but 750 being more common. That gives you pressure around, what, 14,000psi or less?
Some of the better commercial JHP defensive ammo will top that pressure, some up around 18,000 or even 20,000 for some of the Cor-Bon defensive .45LC. That's still not "+P" or "Ruger ONLY!!!", and can be shot in something like a Taurus 2" TI snubbie. This stuff is NOT recommended for the Italian break-tops, at least not in any quantity.
S&W was so worried about that sort of load being used, they made theirs in .45S&W which is a hair shorter so that stuff won't chamber. .45S&W is currently being loaded only in "Cowboy Ammo" at the low pressures stated already, and not any "defensive loads" whatsoever. I don't think any commercial hollowpoints exist in .45S&W, nor jacketed.
Throw a "Ruger ONLY!!!" .45LC+P in an Italian break-open .45LC, and it'll probably blow wide open. My bet would be on the latch failing but the hinge could Chernobyl too.
I think the solution to speedloading a Ruger SA is to go with a double-caliber .45 model, buy the Brownell's fine cylinder hone and polish the cylinders. The part number is in one of the links at this thread:
http://www.thefiringline.com/forums/showthread.php?s=&threadid=80872
Then experiment, and see if the .45LC or .45ACP tends to drop free quicker. You also want to chamfer the back edge of the cylinder bores, so if you start with stainless you can do that without needing to re-blue.
If the .45ACP is working, speedload either from tubes or GI 1911 mags. 45LC would be a tube-only proposition but might otherwise work great. I suspect .45ACP from tubes would be better because with no rim, the plastic tube diameter could be smaller and should fit "into" the loading gate better.
You also want the Power Custom freewheel pawl...again, see that thread above.