Tim Hamilton who has a Youtube channel called "Tactical G-Code" is a prototype machinist that works with very expensive CNC machine tools. I sent him a Lyman lead slug to get the dimensions from, and programmed that into his $250,000 robotic wonder.
He made three clones out of titanium and 6 out of aluminum. Aluminum is a breeze to machine, but titanium is a bit more difficult. The titanium slug (left in photo) weighs about .45 oz (13g) while the aluminum slug weights almost HALF that at .28 oz (8g).
The LEAD version of these weighs 1.1oz (33g)
These lightweight pellets should scream out of a 12 ga shotgun!
Tests coming soon!