"...without that hollow cavity shape, they don't deform..." That's 100% not true. JSP's expand when an HP does not due to a lack of velocity. HP's require velocity to reliably expand. A JSP will expand even if the velocity is lower.
"...wouldn't over expansion ruin a lot of good meat?..." Nope. The soft point rifle bullet is essentially the 'standard' hunting bullet. All the manufacturers make at least one. PSP, Power Point and Soft Point, for example, are all the same thing by Winchester and Remington. However, it's not a good idea to compare rifle and pistol bullet performance. Different things.
"...useless because FMJ 40 does anything an FMJ 10mm..." Irrelevant since any FMJ will make a hole of its own diameter and not much else. There's no comparing any FMJ to any JSP either.
"...wouldn't over expansion ruin a lot of good meat?..." Nope. The soft point rifle bullet is essentially the 'standard' hunting bullet. All the manufacturers make at least one. PSP, Power Point and Soft Point, for example, are all the same thing by Winchester and Remington. However, it's not a good idea to compare rifle and pistol bullet performance. Different things.
"...useless because FMJ 40 does anything an FMJ 10mm..." Irrelevant since any FMJ will make a hole of its own diameter and not much else. There's no comparing any FMJ to any JSP either.