cutting the velocity by 45%.
that's right, a 460 gets a 230gr jhp to 1300 fps in a 4" barrel, and they dont think that the same case can get 70 grs to 2300 fps. Further more, the 70 gr Split Nose is LUBED, CAST, HOLLOWBASED,and its OD is .453". All those issues help increase velocity. Lube and hollow base reduce friction in the bore. Hollowbase seals the bore better, makes more room for powder. A cast bullet seals the bore better than does a jacketed bullet, and it has less friction. In fact, without the hollowbase and the .001" oversize bullet, such velocities can't be had in a 4" barreled, tilting barrel autopistol, because the bullet will just squirt out of the barrel before it can build enough pressure and velocity. High pressures are NOT the issue with such a bullet. Keeping it IN the barrel long enough to build up some velocity is the hard part.
The solid tin bullet is HARD,making for more friction,but it's necessary, to get the bullet THAT light, and to make it AP. Such a bullet of course wont expand, but it WILL frag reliably in flesh, at such speeds, if its pre-weakened by machine cuts, at critical spots on the bullet.
Such a load offers the most one can have in a controlable ccw pistol,in the way of stopping effect. It gets adequate penetration,and it ALSO has maximal shock effect and tissue damage. After the front 2 segments break off, the rear segment is a full wadcutter shape, and it's nose heavy, because of the hollowbase. It's very hard, very sharp cornered,and it shoots thru big dogs, end to end. the 2 other frags typically offer 7=8"of penetration in flesh, and they create separate wound channels, with overlapping, RIFLE softppoint type damage to fragile chest organs, with their temporary gas cavities.
This load has the .45's frontal area, same recoil and momentum as .45 ball, and 30 AK velocities, along with the advantage of being AP and offering 3 wound cavities with each shot. It's just as likely to suffice as is a 223 softpoint,(for the same reasons, shock and tissue damage) and that's PLENTY of power. Yes, it has a lot of blast and flash, but sometimes such are an advantage,in a ccw pistol and "normal times". I dont consider ANY belt pistol to be shtf material,really. shtf means you'd BETTER keep your autorifle at hand, ALWAYS.