Barely Above Heavy Bone Threshold Ultra-EFOC Arrow

[Dr. Ed Ashby]

Rattus58,

From my previous post:

 

You definitely want the diameter of your arrow’s shaft to be less than the diameter of the broadhead’s ferrule. All else equal between two arrows, the difference in average outcome penetration between a shaft diameter smaller then the broadhead’s ferrule and a shaft diameter greater than the diameter of the broadhead’s ferrule is 40%. That’s HUGE!

When all else is equal between two arrows, a tapered shaft out penetrates a parallel shaft, and a parallel shaft out penetrates a barrel tapered shaft.

Regardless of whether the shaft is parallel, tapered or barrel tapered, you never want the shaft's maximum diameter, at its widest point, to be greater than the diameter of the broadhead's ferrule. That applies regardless of the shaft material you are using. Doing so will cost you dearly in penetration. Ideally the shaft's maximum diameter should be AT LEAST 6% smaller than the diameter of the broadhead's ferrule.

Sorry I wasn't clearer on the first post,

Ed

[Rattus58]

Got it... now to figure out how cut my shaft diameters down or find a different broadhead than the snuffer...

Much Aloha... Tom

[slivrslingr]

Chopx2-The Arrow Dynamics shafts are full length tapered.

[Rattus58]

Originally posted by slivrslingr:
Chopx2-The Arrow Dynamics shafts are full length tapered.

What does that mean... full length tapered?

Much Aloha...  :cool:

[slivrslingr]

The point end starts fat and tapers to skinny at the nock end.  I'm not sure what the dimensions are.

[Andy Cooper]

Aren't the Grizzly Stics the same type of taper?

[Rattus58]

Hmmmmmm I guess if you can taper the tailshaft, you could figure out a full length tapering jig.. I'd be curious also in the tapering dimensions... like 23/64 to 5/16 or what?

Dr. Ashby suggests that this might be the ideal for penetration when you really need it...

Much Aloha...  :cool:

[Andy Cooper]

The Grizzly Stiks are tapered from the nock all the way to the point end. I didn't see any dimensions, but I may have missed them. A six pack of those shafts is like buying a box of factory ammo for a 470 NE!

[Rattus58]

Originally posted by Andy Cooper:
The Grizzly Stiks are tapered from the nock all the way to the point end. I didn't see any dimensions, but I may have missed them. A six pack of those shafts is like buying a box of factory ammo for a 470 NE!

 The taper goes thick at the broadhead and skinny at the nock... right?

Much Aloha...  :cool:

[Andy Cooper]

Yes, I didn't state that very well! The nock end is smaller diameter than the point end...like a baseball bat...sorta. More like a throwing dart.

If I'm understanding this EFOC biz correctly, then once the threshold for arrow weight, velocity, and FOC have been reached, then the only reason to go to a heavier draw weight is to be able to shoot a heavier arrow...right?

(Maybe I should quit reading between appointments so I can concentrate better!)  

[Rattus58]

Haha.... I think quitting while you're ahead is good...  :cool:

Aloha....

[Rattus58]

Oh... and thanks....

Aloha...  :cool:

[Andy Cooper]

Can't quite now...I've dreamed of hunting cape buffalo for years. My dream is coming closer.

[Rattus58]

Originally posted by Andy Cooper:
Can't quite now...I've dreamed of hunting cape buffalo for years. My dream is coming closer.

That is my goal too for if not next year, the year after...

I'm told Buffalo is about $15,000 for the hunt, which is right at my limit unfortunately...

Plains game hunting there is cheaper and plentiful too, than an elk hunt.

Much Aloha...  :cool:

[slivrslingr]

You should look at coming to Oz and hunt water buff and pigs (lots of other critters as well).  It's cheaper and likely just as much fun.  That's what my plan is!     :D

[Andy Cooper]

Originally posted by slivrslingr:
You should look at coming to Oz and hunt water buff and pigs (lots of other critters as well).  It's cheaper and likely just as much fun.  That's what my plan is!      :D  

That is something I'm considering doing, too!  

[chopx2]

With all the things I hear about how much you guys have down under, I 'm trying to talk her into moving!

BTW don't tell her about the spiders...shhhhhhhhhh    

I'd love to take a buff there with my buffalo bow.

[Andy Cooper]

Has anyone built EFOC arrows using the Arrow Dynamics Heavy Hammerhead shafts?

[slivrslingr]

I'm working with some regular HH's for my 69# recurve, but am having some issues as it appears they are too weak when full length (the tail kicks left during flight).  I find that hard to believe as they are supposed to spine at about 90#.  I'm running 360 grn. on the front.  I'm hoping to get these arrows sorted and get after some buff next year.  The Heavy's may be stiffer and able to handle more weight on the front, but I'm not sure what their spine is.

Yup, plenty of stuff to hunt here.  One thing to keep in mind is that it's a big country and a long way to anything.  While there are plenty of spiders and snakes that can cause issues, they pretty much keep to themselves, though being cautious never hurts!

[chopx2]

On one of my bows my bare shaft tuning was telling me I needed stiffer spine. I was already at .300 with 415 total up front and at 30" BOP to throat and I had built out the shelf 3/16".  The bow is only 58# @ 29". I had to drop down to 200gr (300 total) tip to get them to fly straight.

I switched to the bare shaft planing method that Adcock proports as the best way and it stopped showing too weak.

Which method should i believe. That is abig difference in spine requirements. I can't believe I need .250 spine shafts for this bow.