There is alot more to penetration than just momentum from a heavy arrow. Those of you who keep demanding everyone must shoot an arrow that weighs over 400 grains or more are ignorant. Depending on the set up a 365 grain arrow can penetrate as much or more than a 400. So many factors go into penetration, KE and Momentum are just two of many. Broadhead style, sharpness, arrow diameter, broadhead cutting diameter, what type of animal, distance, arrow flight, shot angle, weather the animal is tense or not, and the list goes on and on.

Arthur P, Im not sure what you hunt. Really I dont care how heavy of an arrow you shoot, thats your choice and that is prefectly fine, but Ive killed several puny deer that field dress over 250lbs with a 365 grain arrow.I dontsee an additional 35 grains making a whole lot of difference.

Ill quote you here,

Do light arrows work? IF you're knowledgeable enough touse the proper equipment and choose the right broadhead for the amount of power your equipment delivers... IF you're experienced and know how to control yourself under the stress of the moment to make a clean shot... IF you're patient and refuse to take anything but ideal shots... IF you're skilled enough and able to place your shots properly...

Shouldnt all bowhunters do that, regardless of arrow weight. Enough said.