I haven’t shot any animals yet with my setups, so no idea on the penetration yet. But with a draw length of 29.5”, I shoot around a 31.5” arrow because when I buy wood shafting (usually comes at 32”), taper it, and put a nock on it that’s about what it works out to be. When I was shooting carbon a high FOC helped with flight and a heavy weight helped with noise so when I started making wood arrows I stayed did my best to keep those traits.
When I switched to making wooden arrows I picked a heavy common weight for broadheads and points at 190 grains, and a single length go aid in consistent sight picture for instinctive shooting. So I alter the spine for a new bow and brace height while using the same length of arrow and point weight.
So last year I carried a 720 grain 31.5” arrow with 190 grain single bevel glue on point with 23/64 POF shafting. About 11 grains per pound for my old Herters longbow.
I think this year I’m going to try one of the two Bear Kodiak Magnums, I’m deciding if I use the 55lb bow with 720 grain cedar arrows, or the 60 lb bow with some monster 850 grain Western Larch arrows I have made up for it.