arrow build help

[TheTone]

The standard 16grain ones. I did so many dumb calculations of using brass, iron wills, heavy broadheads trying to get to a weight and FOC that people are pushing. Then I ended up buying some black Eagle Spartans and adding point weight. They’re a fine arrow but also the only arrow I’ve ever had inserts pull out of. I got some really bad arrow flight with them a couple years ago right before elk season so I ran to the store and bought some axis 340’s through and my normal broadheads and had great flight and killed a bull a couple days later

 

[BKhunter]

I would recommend sticking with a standard diameter (.244-.246"/6.5mm) shaft for simpler and cheaper insert options that are also generally more durable and more available. IMO the supposed decreased wind drift and increased penetration of a smaller diameter shaft are negligible in practice.

But if you're dead set on a small (.204"/5mm) or micro (.166"/4mm) shaft, a hidden insert (HIT) with collar is the best insert option. A .166" HIT has Deep Six (6-40) threads, which severely limits your broadhead choices. A .204" HIT has standard (8-32) threads. I don't see any real advantage to using a steel Iron Will HIT over an aluminum or brass Easton HIT. Steel is a stronger material, but the strength of the system comes more from the carbon shaft surrounding the HIT than from the HIT itself. I do think a collar is a good idea on a small or micro shaft.

300 or 340-350 spine will likely work best depending on how much weight you want to put on the front and how long you want to cut the shaft. Below is qSpine output for a hypothetical 27.5" carbon-to-carbon Easton Axis 5mm with 175 gr total on the front (head + insert + collar) and 30 gr on the back. 450-550 gr total arrow weight is a good range for deer and elk.

Bow inputs: 342 fps IBO, 27.5" DL, 27" ATA, 6" BH, 85% LO
View attachment 410594

Would you be able to run this with the 31 inch v3 matthews at 70# draw if you don't mind? I have been going over this again and I think I am going to go with the 125g iron will BH, 25 grain collar and 50 grain HIT insert. When I run the numbers I get it very stiff for 300 and very weak for 340 for the axis 5mm. I think I am doing something wrong with the app. I appreciate all your help here.

 

[Mighty Mouse]

Would you be able to run this with the 31 inch v3 matthews at 70# draw if you don't mind? I have been going over this again and I think I am going to go with the 125g iron will BH, 25 grain collar and 50 grain HIT insert. When I run the numbers I get it very stiff for 300 and very weak for 340 for the axis 5mm. I think I am doing something wrong with the app. I appreciate all your help here.

Based on what I'm getting in qSpine, 300 should be near perfect.

Bow inputs: 342 fps IBO, 70# DW, 27.5" DL, 31" ATA, 6" BH, 85% LO

Arrow inputs: 27.5" C2C, 200 gr on front, 30 gr on rear

 

[BKhunter]

Based on what I'm getting in qSpine, 300 should be near perfect.

Bow inputs: 342 fps IBO, 70# DW, 27.5" DL, 31" ATA, 6" BH, 85% LO

Arrow inputs: 27.5" C2C, 200 gr on front, 30 gr on rear
View attachment 426832
View attachment 426831

Thank you!!! I must being doing something wrong with that app. I really appreciate all your help you’ve given me a lot of insight and good educational sources. Much appreciated MM!


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[5MilesBack]

Based on what I'm getting in qSpine, 300 should be near perfect.

Bow inputs: 342 fps IBO, 70# DW, 27.5" DL, 31" ATA, 6" BH, 85% LO

Arrow inputs: 27.5" C2C, 200 gr on front, 30 gr on rear
View attachment 426832
View attachment 426831

How can the dynamic spine be equal at .305 for both those different arrows?

 

[Mighty Mouse]

How can the dynamic spine be equal at .305 for both those different arrows?

I think qSpine's calculated "dynamic" value is supposed to be the static spine needed to achieve optimal flight at the given bow specs, shaft length, and component weights. The "static" value is the selected shaft's advertised static spine. Ideally the dynamic and static values should be equal. In the example above, .305 is the calculated optimal static spine, so the .300 shaft is shown near optimal and the .340 is shown weak.

 

[5MilesBack]

Thanks. I thought the program was calculating what it thought the dynamic spine was for each arrow. So it appears that the program gives a recommended dynamic spine for the "bow" input, not necessarily the arrow input. And the chart shows the arrow input.