Aaron – my bad; I think I was confusing what poundage you were shooting with Lygooshka’s. But if you are thinking of hunting with a #40lb. bow, all the more reason, in my opinion, to dial in the heaviest arrows (or, more specifically, the highest FOC arrows) that your bow will still shoot accurately and consistently, within your desired hunting range. A light bow and light arrows is not a winning combo, imo, unless you’re only planning on using it for small game.
There are those that will tell you that they have taken larger animals, maybe even on a regular basis, with such light setups. But the other side of the coin that doesn’t tend to get mentioned is the many animals that get wounded and have a prolonged death, or even worse – are wounded and not retrieved, as a result of light setups combined with a less than perfect shot. There is simply nothing to be lost by maximizing the penetrating power of your arrows as much as possible, and I’ve never understood why anyone would argue otherwise.
I understand it’s hard, and can be a little costly, to play around with a bunch of different spines and weights to find what you need. Can you give a little more detail on the bow that you’re shooting, and how the shelf is cut? A center-cut shelf will tend to accommodate a wider spectrum of spine than one cut before center.
