I have 4 basic loads all developed for the bersa, the PT58HC is a new toy;
2.8gr SR4756, xtreme plated 100gr, extremely accurate but not reliable to cycle bersa, fte/stovepipes common, use as training round by tossing a few into a hundred pack when I box them up, not tested in Taurus
4.2gr SR4756, xtreme plated 100g, slightly large than golfball grouping from rested weapon, extremely consistent not tested in taurus
4.0gr SR 4756, LRN 95gr from Badman, same performance as above, tested in taurus with same poor performance as hand cast
4.0gr SR4756, LRN 105gr WW alloy from Lee mold, same performance in bersa above poor performance in taurus, worse than badman rounds, lubed with two coats of alox.
3.8gr Unique, Hornady XTP, 120 rounds proven in bersa with grapefruit size accuracy at 25yards from rest, not tested in taurus yet as I need to make some more up.
All my cases are trimmed to .677, all use WSP, mixed brass (only nickel is segregated for XTP rounds) I also set my OAL on all above to .950. All rounds are ran through a lee factory crimp, and finally pushed through a bulge buster. Other than the XTP rounds I have approx 3500 rounds of the others listed mix/match through the bersa with never a single fault unless running the 2.8 gr, the shoot clean, low smoke, almost no muzzle flash and never an effort to clean the bore. The unique is a bit poppy however that is by design as those are built specifically to push the little XTP near 1100 fps (some of us knew that this bullet was before shootingthebull410 proved it with the precision one rounds
I've gone from the 2.8 up to 4.2 gr of SR4756 but I've yet to make a 3.5gr scoop, it's on my list
The 4.0 standard is convenient as it is a consistent scoop for my setup, the other loads are dropped from a lyman 55.