ORIGINAL: mobow
I agree that high FOC arrows are certainly very stable in flight, my current set up yields 12% FOC. They fly extremely clean.
I'm just thinking outloud here, but how much of this is overkill? What I mean is, I'm shooting a 480 grain arrow, 12% FOC, I'm getting 84 #'s of KE, and while I'll admit I don't know a whole lot about momentum, I'm thinking I have quite a bit. If we're talking about whitetails, all we're really doing now is determining how far in the ground the arrow will be after blowing through said deer. Moose, cape buffalo....Ok, maybe that's not enough, I just don't know.
I'm not arguing here, just thinking. Someone tell me what I'm going to gain by adding another 9% FOC. My arrows are flying like fickin laser beams attached to my frickin bow.....And they hit like a tank. They fly extremely clean, they're almost fun to watch in the air.
Yes - for whitetails it's probably not necessary. BUT - on a marginal shot that smacks square on the front shoulder bone I'd like to know that I'm going to blow right through the thick part of that shoulder bone with no problem.
There have been other times when I didn't get a passthrough because I hit that shoulder bone on the way out. Maybe a 500+ grain arrow with 21% FOC and a good fixed blade broadhead would have given me an exit hole.
The third reason is fixed blade broadhead flight.Maybe you want to shoot the biggest fixed blade broadhead you can find, like a G5 Striker Magnum which has a 1.5" cutting diameter. A 21% FOC would sure help your vanes steer that big old head and make it fly like a field point.
These are some of the reasons I can think of. There might be more.