[badlucklottery]

Solid copper projectiles are the primary leadless solution on the market but they're much more expensive than the traditional copper jacket over lead core construction.

There's also solutions like Federal Syntech (https://www.federalpremium.com/handgun/syntech/) that doesn't get rid of the lead but fully encapsulates it to avoid the airborne lead problem.

[keepamovin]

It’s pretty interesting how the deformity and thermal properties of the metal would affect ballistics. I guess silicon is too brittle even though it’s cheap and plentiful and aluminum is probably too light.

That poly is also interesting. the R&D they would’ve had to do to discover a polymer that would contain an exploding bullet as much as possible

[lazide]

Thermal and deformation properties of the metal have no impact on ballistics at all?

Density sure does though.

Which is why 99% of the stuff you’re mentioning doesn’t really work.

Copper is quite dense, but still not as dense as lead, which is why it kinda works. Steel is terrible (but not completely useless). Tungsten works awesome (as does silver and gold), but is cost prohibitive except for specialized applications.

[kayfox]

In addition to Federal Syntech there is Speer Lawman, which is a bullet type called TMJ or Total Metal Jacket. Lawman has lead free primers. There is a green box variant called RHT that does not use lead in the bullets.