NAP Nitrons are not the largest head but shoot well and leave a great exit hole. I usually shoot the NAP Crossfire's which spin, but I am not shooting super fast. I do know someone shooting around 310 that uses them and they fly well.

Side Note--Have you chronoed that bow with a hunting arrow yet? I know that the 82nd is fast but 340 fps? Make sure you are shooting a stiff enough spine, you might also need to look at your fletching combo to help with your arrow flight.