Filling that cavity with "P-Tex" ski base repair plastic, or just common epoxy kicks the chit out of expansion ratios too.
Hell, try cutting "Dum Dum" grooves into it,....you can than hear it whistle on it's way down range.
You'll not be HITTING anything, but if you want to freak out your fellow shooters,...drill a hole through the front of a bullet,.....they'll land in the general vicinity of where your barrel's pointed,.....and make a blood curdling shriek, so doing.
Screamers,....hard on morale, back in the day, funnier than hell now.
GTC
A young lad [first time deer hunter] in our group is already freaked standing downrange listening to the humming bird whine of the incoming Sharps, think he needs discovered to those "screamers".. That'll be worth a video later!
