Here we run with a standard of 280fps max and use ONLY .25g bbs. When we thought about it, we felt we didn't need the mercy rule and thus, abolished it. Mercies here come as a result of being polite rather than safety.
If it's a safety issue, you're going to have to go with the highest fps allowed with the heaviest weight for simplicity. Find a decent mercy range for 400fps with .28g. (I don't really find many AEG users going beyond that...and snipers at 450fps with .43g have their own set of mercy rules.)
Another thing, what's the appropriate surface energy transfer for such a shot? And what's the acceptable fps and energy of impact? Should all players be forced to wear long sleeves for protection? There's a lot of variables to account for. A blanket policy makes sense to go with.
Age Verifier - Lower Vancouver Island
Brotherhood of Nod - Nod Prime || Vancouver Island Airsoft League - President