Well DIY its like you said in you first post. This will likely only appeal to <10% of the bow hunters out there. I ran your calculations and they are correct. With your set up you do get 77.7 FTLB KE. But with that heavy arrow you're sacrificing a lot of speed (just maybe a tad better than we used to get with a standard recurve bow and average weight arrows way back pre-compound). I also ran my set up through the numbers and my 420 gr arrow at 305 FPS gets me 86.7 FTLB KE.
That's 11.6% more energy and a 45% speed increase.
And while I'm sure your set up would be good for extremely large game like the big bears and possibly even elk at close range because of the momentum it has I really don't see the need for such a set up on whitetails.
But I do admire your ingenuity and your passion for the sport. Good luck BTW that tenderloin looks delicious!
Last edited by bronko22000; 01-21-2021 at 05:35 AM.