In my opinion the main focuses should be:
1) Will silicon BB's cause more damage to hard(er) surfaces? Such as glass, guns, eyewear, teeth?
I'm very confident they do, but plan to do my own testing. Kokanee's lens results already leads me to confirm this is true.
2) Do heavy weight BB's cause more damage to hard surfaces? (hopefully Kokanee does a test on his lense).
3) Do silicon or heavy weight BB's cause more damage to soft tissue?
I'm fairly confident that both are NOT a concern. Perhaps knuckles and teeth in the case of silicon BB's.
4) Are the current ANSI, CSA and Milspec standards sufficient for silicon BB use?
Ronin 49 Team Member