An offer to help

[konrad]

Sounds interesting!
07 Bear Truth (hard cam)
60 pound draw
29 inch shaft
27 inch draw length
2 inch Blazers

The question is: What spine arrow and weight broadhead will give me a 19% FOC balance point?

I currently use a 2413 with 100 grain points, Bohnig signature nocks and 2 inch blazers.
My FOC is almost 11%.

Thanks for the help,
Konrad

Your current setup: Recommended spine: .434, your spine: .365, so it's off the charts stiff.  The numbers: 231 fps, 10.68% FOC, 58.1 ft-lbs KE, 489.5 grain arrow.  Arrow drop 20-50: 58", KE at 50: 47.1 ft-lbs

To get above 19% FOC....You can stay with your current arrows and unglue the inserts and cut them to 28" (too weak at 29") and use a 225 grain broadhead.  I'm guessing you got the >19% from Dr. Ashby's research on penetration, and this is what he used to get that FOC:  Grizzly broadheads and steel weight adapters.  I followed the same logic this year and bought from these guys with no problems, but I haven't sent one through an elk yet to give you a report, but I can tell you that they get sharper than ****:
http://www.braveheartarchery.us/new_page_5.htm
http://www.braveheartarchery.us/new_page_23.htm

With your newly cut 28" 2413 arrows and 225 grain broadhead, then the recommended spine becomes .369, and your arrows are .365, so you're good there.  The numbers for this new arrow: 207.8 fps, 19.11% FOC, 57.9 ft-lbs KE, and 604 grain arrow.  Arrow drop 20-50, KE @ 50: 73.1", 47.1 ft-lbs.

To go with a carbon, I'll pick a weight forward arrow by design, Carbon Express Maxima Hunter, and the best broadhead made, Silver Flames.  For a 29" arrow and 210 grain Silver Flames, the recommended spine would be .373, and the Maxima Hunter 350's are .337 spine, so they'd be stiff but should work just fine.  The numbers for this setup: 226.6 fps, 19.43% FOC, 58.4 ft-lbs KE, 512 grain arrow.  Arrow drop 20-50, KE at 50: 59.8", 48.6 ft-lbs.

Good luck in your pursuit!

Thanks Todd,

Your program’s speed and FOC calculations are right on for my arrow configuration.
Yes, I have read almost all of the good doctor’s reports.
I choose the 2413’s using the Easton shaft selector program and they seem to work admirably as far as I can reliably see (60 yards).

I will save your data for reference as I will be going to the 19% some time soon for experimentation.
The Grizzly single bevels make a lot of sense and that is on the list too.

I like the idea of using battleship technology (Grizzly/EFOC/600 grain total arrow weight) with supersonic power systems (modern compound platform)!

Thanks again,
K

[PYSEEKER]

Todd,
Can you run these numbers?

2006 Allegiance
28" draw
set @ 64#
Trophy Taker full capture
28" AC Super Slim 400's X knock
100 grain Shuttle T 3 blade
2" Blazers
D-loop

[Todd_ID]

Todd,
Can you run these numbers?

2006 Allegiance
28" draw
set @ 64#
Trophy Taker full capture
28" AC Super Slim 400's X knock
100 grain Shuttle T 3 blade
2" Blazers
D-loop

No problem.  This is all figured at 65% letoff, but going to 80% only drops the speed by about 1.5 fps, so it'd be very similar numbers.  It looks like the recommended spine for your setup is .378, so your .400 spines are a little weak, but not too bad.  If you went to a 125 grain head, then you might have troubles with them flying straight, but they probably are flying fine with the 100 grain heads.  You are at 281 fps, 12.01% FOC, 72.4 ft-lbs KE, and 411.6 grain arrow weight.

Arrow Drop 20-50, KE at 50
29.2", 62 ft-lbs

Wind drift in 15 mph 90 degree crosswind at 50 yards is 6.1", and that's about as low as I've seen, so the Super Slims are looking pretty good there!

[PYSEEKER]

 That program is pretty cool. The numbers are really close. It actually shoots 279fps and the arrows weigh 420. Thanks for taking the time to run the numbers...

[Hornseeker]

Cool Todd, I just got this bow yesterday... is this program to give me the results of my setup or to help me Get setup??? I know almost nothing about compounds and tuning them... I do know this.. I have like 5 dozen brand new axis 400 shafts... so am hoping to use them.... Here's what I know...

2009 Hoyt Alphamax
27" draw
set @ 70#
Fuse double prong drop away..(dont know exact model)
Dont know arrow length, but would like to use Axis Camo 400's (they are 9.8 per inch)
No preference on broadhead yet... would probably like 125 though??
3 Fletch, blazers or standard, whatever...
D-loop

Need anymore info?? I guess my main question is what length to cut these 400's to in order to get them to spine good with this bow and a 125 point? Or will I have to go with a 100 point??? Hope not, I like a little more FOC.

Ernie

[Hornseeker]

Oh, its an Alphamax 35...just so you know....

Also Todd...can you tell me what I'd need to do to get a big old broadhead and high FOC going? I am talking about a 175 grain head WITH a 100 grain steel adptor.. Or... a 175 head screwed into a 100 grain brass insert...

Do I need the 300s???

Thanks!

[Todd_ID]

Cool Todd, I just got this bow yesterday... is this program to give me the results of my setup or to help me Get setup??? I know almost nothing about compounds and tuning them... I do know this.. I have like 5 dozen brand new axis 400 shafts... so am hoping to use them.... Here's what I know...

2009 Hoyt Alphamax
27" draw
set @ 70#
Fuse double prong drop away..(dont know exact model)
Dont know arrow length, but would like to use Axis Camo 400's (they are 9.8 per inch)
No preference on broadhead yet... would probably like 125 though??
3 Fletch, blazers or standard, whatever...
D-loop

Need anymore info?? I guess my main question is what length to cut these 400's to in order to get them to spine good with this bow and a 125 point? Or will I have to go with a 100 point??? Hope not, I like a little more FOC.

Ernie

Ernie,
At first glance I thought there was no way the 400's would be stiff enough for that hot new bow.  The saving grace is the shorter draw length allows a shorter arrow; they will work perfect cut at 27" with 125 grain heads since the recommended spine is .402.  The numbers: 261.9 fps, 14.64% FOC, 65.38 ft-lbs KE, 430 grain arrow weight. 

To use the heavy stuff you mentioned, then you'd be looking for a .320-.330 spine: I'll give you numbers from the Cabela's Stalker Extreme in 65/80 which is a .320 spine.  Most likely any of the 340 class arrows would likely work, though, as long as you kept them 27" or shorter.  Cabela's w/ 275 grain heads: 235 fps, 24.85% FOC, 68.6 ft-lbs KE, 559 grains.

Arrow drop 20-50, KE at 50
Axis 400's w/ 125 grain: 34.6", 56 ft-lbs
Cabela's 65/80 w/ 275 grain: 44.5", 58.5 ft-lbs

[D-Rock425]

can you run these numbers
hoyt aphamax 35
65 pounds
27 draw
28 gold tip pros 5575
85 grain tips
QAD ultra rest
2 blazers
d-loop
I think total arrow weight is about 350 grains

[Hornseeker]

Cool...good to hear, cause I was shooting my axis 400's with 125's today and they are flying GREAT! I also rigged up one 340 at 26" with a 100 grain brass insert and a 125 head and it seemed to be fliying great too!!

Thanks...

[Todd_ID]

can you run these numbers
hoyt aphamax 35
65 pounds
27 draw
28 gold tip pros 5575
85 grain tips
QAD ultra rest
2 blazers
d-loop
I think total arrow weight is about 350 grains

No problem! I don't see any problems on your setup.  Recommended spine is .440, and yours are .400, so they're a bit stiff, but probably ok.  The numbers: 268 fps, 11.6% FOC, 56 ft-lbs KE, 355 grain arrow weight.  With enough stiffness to spare, you could go to 100 grain heads with no problems to get a little heavier.  The numbers for 100 grain heads: 265 fps, 13.2% FOC, 57.7 ft-lbs, 370 grains.

Arrow Drop 20-50, KE at 50
85 gr: 33", 48 ft-lbs
100 gr: 33.8", 49.02 ft-lbs

[Hornseeker]

Hey Todd,

Run the number for that same bow, Axis 340, 26" with 100 grain brass insert, 125 grain broadhead, 3 fletch... What kind of FOC and FPS and KE am I getting there??

Does your program pump out momentum numbers?

Ernie

[Hornseeker]

I forgot to mention, those axis 400's are camo and are 9.8 gpi...

[D-Rock425]

can you run these numbers
hoyt aphamax 35
65 pounds
27 draw
28 gold tip pros 5575
85 grain tips
QAD ultra rest
2 blazers
d-loop
I think total arrow weight is about 350 grains

No problem! I don't see any problems on your setup.  Recommended spine is .440, and yours are .400, so they're a bit stiff, but probably ok.  The numbers: 268 fps, 11.6% FOC, 56 ft-lbs KE, 355 grain arrow weight.  With enough stiffness to spare, you could go to 100 grain heads with no problems to get a little heavier.  The numbers for 100 grain heads: 265 fps, 13.2% FOC, 57.7 ft-lbs, 370 grains.

Arrow Drop 20-50, KE at 50
85 gr: 33", 48 ft-lbs
100 gr: 33.8", 49.02 ft-lbs

thank you todd ID

[Hornseeker]

Todd,

Will this program run these extreme numbers? I need to buy some stiffer shafts and I'm trying to figure out if I can go with 340's or need to jump to 300's...

Here's my thought as above.. and you gave me the Cabelas arrow I needed, but I am going to buy axis arrows... IF I go with the 300, and need a 320 spine, I can just cut it a little longer right? OR...I can probably stick with the 340 and use it at 26"?

It is conceivable that I will have the Axis shaft, on the 70# AM 35... 27" draw... with a 100 grain insert and possibly up to a 290 grain head, but most likely something from 175-220... (I know, its retarded, but its fun!!)

Thanks for  your help!

Ernie

[Todd_ID]

Todd,

Will this program run these extreme numbers? I need to buy some stiffer shafts and I'm trying to figure out if I can go with 340's or need to jump to 300's...

Here's my thought as above.. and you gave me the Cabelas arrow I needed, but I am going to buy axis arrows... IF I go with the 300, and need a 320 spine, I can just cut it a little longer right? OR...I can probably stick with the 340 and use it at 26"?

It is conceivable that I will have the Axis shaft, on the 70# AM 35... 27" draw... with a 100 grain insert and possibly up to a 290 grain head, but most likely something from 175-220... (I know, its retarded, but its fun!!)

Thanks for  your help!

Ernie

OK, the Axis 340 would work at 27" with 275 grain head. 23.4% FOC, 593 grains, 228 fps, momentum at 40: .5652.  The 340 at 26.5" with 320 grain head: recommended spine is .328, 25.5 % FOC, 220 fps, momentum at 40: .5818. Your previous 400's with 125 grain momentum at 40: .4697.