Or, you can just skip the jury rigging, and go for the good stuff — 9mm through denim and into gel:
What if, you put a ball bearing in the center?
Speaking of jury rigging, be mindful of what a talented prosecuting attorney could do with exotic ammunition as evidence.
And also that some states have ammunition type restrictions. Modifying a bullet could put you in seriously hot water, even if you don’t use it.
Be careful. The added weight of the ball bearing to the projectile might produce too much chamber pressure.
If you can’t make it float is it any good?