Back when the handgun world "revolved" the wadcutter bullet was the premier target load. A wadcutter is a cylinder of lead, which cut nice clean holes in paper targets. They came in two basic styles, Bevel Based (BB) and Hollow Based (HB). Normal weight for .38 cal was 148gr.
They are neither designed, nor intended for high velocity. Normally made of dead soft lead, often by swaging, they are intended as target bullets, moving at slower than full speeds (for reduced recoil), and tend to be very accurate.
You need to understand the difference between full wadcutter (WC) and semi-wadcutter (SWC) shapes. The full wadcutter is just a lead cylinder, flat on the ends, or nearly so. The semiwadcutter has a wadcutter shaped base section, but a tapered nose with a flat point.
The Keith style SWC, most common to day in one form or another has a sharp full diameter shoulder at the base of the nose section. This design has proven not only very accurate, but when cast of hard lead alloy is capable of being fired at high speeds, and excellent results in penetration. Hard case SWCs do not usually expand, but they do work well and are the preferred bullet for many hunters as well as for self defense. And the full diameter shoulder also cuts nice clean holes in paper targets.
Many people have tested wadcutters for defense loads, and the results are underwhelming...the factory target loads do not hit as hard as regular service ammo. Lower velocity, less ft/lbs energy and also less penetration.
You simply cannot load wadcutters to full velocity and get good results, the bullets are not constructed to take it. If you are casting your own, and use a hard alloy, you could, but mass market wadcutters are target slugs, only. (ok, they will do fine on small pest animals as well)
I (and many others) have also done a lot of shooting with hollow based wadcutters, seated upside down, so they have a HUGE hollow "point". Again, you cannot drive these bullets fast, but my experience is that loaded down, say 650-700fps they are excellent for small critters, have virtually no recoil, and very little penetration.
Many years ago testing on an old refridgerator showed that at about 10yds, many rounds did not penetrate the fridge wall, although some did. The ones that didn't were laying on the ground in front of the fridge, expanded to about the size of a quarter, after leaving a deep dent in the metal.
I would not recommend a load like this for self defense, because its low power and penetration would not guarantee the bullet would get in to the vitals, and reliably stop a determined attacker.
However, I think that at close range, 5 or 6 of these loads dumped rapidly into the middle of an attacker would give them serious injury, and might just change their minds, even if not physically stopping them.
Make no mistake, they can, and will kill. They are not less lethal, or less than lethal, wadcutters are deadly ammo, and have killed a number of people over the years. What they aren't, is reliable stoppers, and should not be chosen for self defense ammo, other than as a last resort.
