I think cast bullets are fine in many personal defense situations. I will sometimes carry a 629 Mountain revolver, and I load it with one of the “softer” cast 240 gr. SWC BB bullets that are on the market. I load them to about 1000 FPS.

A while back I came across an interesting old article about the .41 Magnum. The old .41 Magnum Police Load was a mid-range load with a 210 SWC, and it is reported to have had very good results in personal defense situations. If you research some of the one shot stop data, this load is in the 75% or better range; not too bad for a “low-tech” round. I think any .40 or bigger caliber, of at least 200 grains cast with a fairly wide meplat (most SWC designs), and greater than 950 fps will do an adequate personal defense job.

Regards