Well I come up with the epics weighing 375 grns if I let the program figure it up, but I figured it at the weight you gave me. I assume the speed you have listed in your sig is with the 400 grn arrows?

If that is the case they still show up weak. The C2 epic 300's spine perfect according my software with that length, tip weight and fletching. It shows them weighing 401 grns though, so if your arrows now weigh 403 grns figure on the 300's weighing around 425 or so. It would drop your speed down to about 280 fps or so. Then again maybe not if your arrows are currently under spined you may be losing speed from it. The proper spined arrow may be more effecient and come out of your bow better possibly getting you some more speed. So you may not lose any, however the slight amount you will lose will not be noticable.

You are currently shooting a mechanical broad head which is pretty forgiving as far as flight goes. I bet if you switched to a fixed blade head you would have some problems with those arrows flying well. Also, while mechanicals are forgiving of flight problems and spine as far as impact points go, they do not perform well with an out of tune bow or weak arrows.

Not that they won't work, you have plenty of power to use them, but they could work better with a properly spined arrow and a well tuned bow. If you had a light set up like mine you would be able to tell the difference in performance on game very easily. It would be the difference between a pass thru and a possibly wounded animal.

Good luck and let us know what you find.

Paul