I'm looking for input from those of you who have experience using the concepts/methods of Dr. Ashby. First, let me say that I am not looking to start a debate or looking for reasons not to adopt Dr. Ashby's methods. What I am looking for is recommendations or tips regarding a setup for the parameters I'm outlining below:
1. Compound bow (Hoyt AlphaMax)
2. Shaft length 28.5" (excluding broadhead & nock)
3. Achieve a FOC of 20% or >
4. Abowyer Wapiti 175 Grain Single Bevel Broad Head
5. Total arrow weight (broadhead/inserts/shaft/etc) of > = 600grns
Any info regarding shaft selection, tuning, fletching, inserts, even alternate broadheads would be appreciated.
Being able to meet all of the above criteria is a bit difficult. That heavy of an arrow with a FOC > 20% is tough. To get close you will have to get a heavy insert. Brass inserts are available at Three Rivers Archery (and most likely other places as well) in 50 and 100 grain. Also, there are weight adapters available that screw into the back of an aluminum insert. The 'problem' with them is that they are farther back in the arrow making a high FOC more difficult to achieve.
Making a few assumptions (65 lb draw, 29" draw) you can get close with a .300 spine arrow. However, as you increase draw weight, the spine of the arrow becomes insufficient - even with .300 spine. A FMJ will get you close in arrow weight but the FOC is only slightly above 17%, an ACC (3-71) is closer in FOC (19%), but only weighs 535 grains. The above is with a 50 grain insert. To accomplish what you are after would need around 100 grains of insert. With that much weight up front you would have to turn your bow down or the spine of the arrow would be too weak. At 60 lbs the spine of a .300 a 28.5" arrow would work. The FMJ would weigh 644 grains and have a FOC of 19.6%, while the ACC would weigh 587 grains and have a FOC of 21.5%. BUT you would have to turn your bow down to 60 lbs. This would be with Blazer vanes and no wrap. The FOC could be bumped a bit with feathers, but that changes the spine of the arrow, which in turn changes that how much draw weight can be used....
All of this stuff depends on draw length, draw weight, ATA of your bow, shaft length, wrap weight, fletching weight, nock weight, d-loop weight, if you have a brass nock set or not, if you have silencers on the string.........