Richard Atkins in 2021
https://www.shootinguk.co.uk/reviews/ammunition/non-toxic-ammunition
BioAmmo Blue...launches a new type of shot that comprises an alloy mix of four metals: bismuth, tin, zinc and aluminium.
With none of the ingredients being so dense as lead, the alloy pellets are obviously lighter, size for size, than lead. 10 Blue alloy pellets weighed 15.4 grains and 10 No 5 lead weighed 19.6 grains. (That is about 22% less)
The crush test figures show the pellets are substantially harder than lead shot...(though) substantially softer than steel, but we must assume that pellets are still best kept away from barrel walls.
Speed of the load was 1371 fps at 2.5 meters from muzzle, which would be close to 1400 fps at the SAAMI 3 feet standard.
Pressure of the 27 gram = .95 oz. load was 8688 psi


https://egunroom.com/bioammo-blue-shotgun-cartridges/
This alloy is softer than steel but slightly harder than lead: using the Vickers hardness test lead has an HV (the unit of hardness) of 45, steel has an HV of 120, whilst Bioammo’s alloy sits between them with an HV of 60


BioAmmo USA
https://bioammo.es/archivos/2021/12/BIOAMMO-USA.pdf