First off, OUCH!! Those things have got to hurt.
Not as bad as getting a dogpile beatdown from Johnny Law, but still.
Those are some nice saps and blackjacks.
If I were a cop, I'd rather use those than shock toys.
Tasers/stun guns don't work on everyone.
Not all of us are bothered by/scared of/subdued by electric shock.
And, shooting suspects should be a last resort.
I'd imagine that thick, dense rubber sap would hurt like the Dickens.
Wonder how well polyurethane would work?
Would be easy enough to make a plaster mold and cast some.
Many years ago (before, during, and after Lexan hit the market) my dad worked for a plastics supplier.
Several Atlanta cops had him make short jacks/headknockers about 12" long with a lanyard from Teflon rod, about 1.5" diameter.
They told him it didn't leave a mark.
I never quite believed that.
I always figured they wanted it because of the weight/density of Teflon.
Those 12" long Teflon jacks were quite heavy for their size.
IIRC, I still have one somewhere.
My dad had two that he had made for himself.
He gave one to me.
I still have it, if I haven't used it to make Teflon machine bearings.