help me select components & weights

[5 shot group]

So this will be my first arrow build and I would like some help in reference to weights vs speed. I know, I know, there are several threads on this already and I have looked through them. Work is slow and nobody here bow hunts, so I thought I would ask my fellow roksliders. Thanks

27" draw, 65 pounds.
For elk and mule deer.


Build #1 (heavy)
239grs shaft (bea rampage 300 @ 8.7 gpi, cut at 27.5")
125gr broadhead (iron will S)
25gr collar (iron will)
50gr insert (iron will)
27.6grs veins (aae max stealth. 3@ 9.2grs ea)
22grs nock (nocturnal)

488grs / 252fps / 68.8 ft-lbs / 13.9% foc


Build #2 (light)
239grs shaft (bea rampage 300 @ 8.7 gpi, cut at 27.5")
100gr broadhead (iron will S)
10gr collar (iron will)
25gr insert (iron will)
27.6grs veins (aae max stealth. 3@ 9.2grs ea)
22grs nock (nocturnal)

424grs / 273fps / 70 ft-lbs / 9% foc

Build #3 (schmedium)
239grs shaft (bea rampage 300 @ 8.7 gpi, cut at 27.5")
100gr broadhead (iron will S)
10gr collar (iron will)
50gr insert (iron will)
27.6grs veins (aae max stealth. 3@ 9.2grs ea)
22grs nock (nocturnal)

449grs / 265fps / 70 ft-lbs / 11% foc


From all the threads I have read, it seems like there are two groups of people on this. One group wants faster arrows so pin gaps are smaller and errors in distance are not as big. The second group wants heavy arrows for when things get dirty and a shot wasn't as good as they had hoped for.

I know the heavy build will hit pretty dang hard, but is also fairly slow. The light build is fast, but I'm afraid it might not be enough if I have a misplaced shot. Then the schmedium is well, in the middle.

I have hunted elk with a rifle before and know shot placement is key, but being my first year with a bow, I am practicing for a good shot, but know it might get messy.

If it helps with your decision, I will be replacing the zebra strings on my bow and when done, I am hoping it will pull a true 70lbs (mods are for 70).

I know there are different schools of thought on this, but I am looking forward to the reasonings.

Thanks.

 

[Zac]

I voted for 2 but that's based on a Western hunting scenario. If you shoot Max 30 yards out of a tree stand it probably doesn't matter.

 

[MattB]

Presuming 300 is the deflection (.300), I am guessing the heavy combo probably won't spine so would look at the medium to see if that would.

 

[Beendare]

A guy can way over think this.

#1) You are shooting a compound- energy to spare

#2) you are shooting an efficient BH that will perform with light/med/heavy arrows

They all work..... the ones you have listed, 60 gr is really not all that much different.


Arrow weight is always going to depend on what criteria you put more emphasis on.

My criteria is a blend of quiet bow...and decent arrow trajectory...so I shoot a 500 gr hunting arrow. Another guy that wants a little better trajectory at longer ranges would go 420-ish. Still another guy only shooting short shots might choose 600gr for a whisper quiet bow.

_____

 

[Mighty Mouse]

Of the 3 options presented, I'd choose the heavy one (then add another 50-100 gr ).

FYI, whatever calculator you're using to estimate speed/KE appears appears to be off a bit. In all the arrow testing I've done, KE has always increased with increasing arrow weight. For example, below is KE vs. arrow weight data I collected a few years ago before and after swapping cams on a Mathews Heli-m I had recently purchased. At the time, I only took arrow weight to ≈500 gr, but I later did additional testing up to 650 gr and KE kept increasing.

An arrow's KE comes from the potential energy developed in the bow during the draw cycle and transferred to the arrow during the shot. A bow's PE is a function of draw weight, draw length, brace height, cam profile, and let-off percentage, and PE remains fixed as long as those parameters aren't changed. With modern compound bows, ≈90% of the PE developed gets transferred to the arrow. The other 10% is "lost" to friction in moving components, acceleration of the string and accessories, continued movement of the string after the arrow decouples, and vibration of the limbs/riser. These losses are perceived as noise and "hand shock." The amount of PE developed in the bow is fixed, but energy losses decrease with increasing arrow weight; thus, a heavier arrow receives more energy from the bow than a lighter arrow (and the bow tends to be quieter with less post-shot vibration). The KE increase is relatively small though, and for practical purposes, KE can be assumed to remain constant.

I've heard it claimed that there is a point somewhere in the multi-thousand grain realm at which arrow KE will decrease due to the bow beginning to "recoil" against the arrow during the shot. I can't confirm that claim, but it sounds reasonable. All my testing has indicated that for realistic hunting/target weight arrows, KE increases (slightly) with arrow weight.

 

[5 shot group]

Presuming 300 is the deflection (.300), I am guessing the heavy combo probably won't spine so would look at the medium to see if that would.

Curious why you think the heavy one won't spin (stabilize?)? Do you think a 300 spine is too light?

 

[nphunter]

Curious why you think the heavy one won't spin (stabilize?)? Do you think a 300 spine is too light?

This is with the heaviest setup, the lighter will show even stiffer.

 

[5 shot group]

My criteria is a blend of quiet bow...and decent arrow trajectory...so I shoot a 500 gr hunting arrow. Another guy that wants a little better trajectory at longer ranges would go 420-ish. Still another guy only shooting short shots might choose 600gr for a whisper quiet bow.

_____

That is the blend I am looking for. I don't need a speed demon, and I'm not hunting cape buffalo. I guess what I am really asking is if a 488gr / 250fps arrow too slow? Would going to the 449gr / 265fps be that big of an improvement?

In the gun world I would take the extra projectile weight and eat the 15fps, but with archery, these things seem much more influential.

 

[5 shot group]

Of the 3 options presented, I'd choose the heavy one (then add another 50-100 gr ).

FYI, whatever calculator you're using to estimate speed/KE appears appears to be off a bit. In all the arrow testing I've done, KE has always increased with increasing arrow weight. For example, below is KE vs. arrow weight data I collected a few years ago before and after swapping cams on a Mathews Heli-m I had recently purchased. At the time, I only took arrow weight to ≈500 gr, but I later did additional testing up to 650 gr and KE kept increasing.

An arrow's KE comes from the potential energy developed in the bow during the draw cycle and transferred to the arrow during the shot. A bow's PE is a function of draw weight, draw length, brace height, cam profile, and let-off percentage, and PE remains fixed as long as those parameters aren't changed. With modern compound bows, ≈90% of the PE developed gets transferred to the arrow. The other 10% is "lost" to friction in moving components, acceleration of the string and accessories, continued movement of the string after the arrow decouples, and vibration of the limbs/riser. These losses are perceived as noise and "hand shock." The amount of PE developed in the bow is fixed, but energy losses decrease with increasing arrow weight; thus, a heavier arrow receives more energy from the bow than a lighter arrow (and the bow tends to be quieter with less post-shot vibration). The KE increase is relatively small though, and for practical purposes, KE can be assumed to remain constant.

I've heard it claimed that there is a point somewhere in the multi-thousand grain realm at which arrow KE will decrease due to the bow beginning to "recoil" against the arrow during the shot. I can't confirm that claim, but it sounds reasonable. All my testing has indicated that for realistic hunting/target weight arrows, KE increases (slightly) with arrow weight.
View attachment 185490

I am using the free calculator on the gold tip website and one from archery calculator .com. like I said, slow day at work and i found these with a simple web search. I knew they would only be a close guess, but I figured it would give me some numbers to compare and for others to see.

I believe I saw a video iron will had where it took only 14ft-lbs to penetrate a deer hide with their broadhead. I know you need to account for possible bone and other "debris", so more should definetly be better

 

[Jimbob]

If your mods are 70lbs and you are only pulling 65 something is WAY out of whack. Get that taken care of first.

When building arrows you want the spine to match your set-up. When you start playing with specs and components you are changing the spine.

These variables cause more flex in the arrow: increase point weight, decreased nock end weight, longer arrow, softer spine arrow, increased poundage, increased draw length

These variables make it flex less (stiffer): decreased point weight, increased nock end weight, shorter arrow, decrease poundage, decreased draw length.

So if I add significant point weight to an arrow making it flex more I then need to change another variable to make it flex less so it stays at my correct spine.

You want the spine of the arrow to match your bow so you have the best accuracy possible.

So play with arrow spine and arrow length to get it to match your set-up. You could go to a 350 shaft cut it a little shorter and this might give you the perfect weight, speed, spine and FOC you want.

AAE max stealth vanes only weight 7.5 grns

What bow do you shoot? this effects what spine you need because of cam/bow design

 

[Jimbob]

If you stay at 65 lbs

go 350 rampage with 100 grain point, 75 grain insert/collar 26" total length with nocturnal
Total weight - 432grains speed -~270 fps FOC- 15%
This spines perfect for 65lbs on software program

If you move to 70 lbs
go 300 rampage 100 grain point 75-grain insert/collar 27.5" length with nocturnal
TAW - 458. Speed ~276. FOC - 14.4%
This spines slightly stiff.

Both of those above options spine nicely and give good FOC.

If you shoot the 300 at 65 lbs it will be a stiff arrow at the heavy point weight and EXTREMELY stiff at the lighter point weights.

 

[5 shot group]

This is with the heaviest setup, the lighter will show even stiffer.
View attachment 185495

1 what is that program called a do you think it is worth it?

2 does it allow you to add components (weights) and see how it affects arrow spine or is it based on something else?

 

[5 shot group]

If your mods are 70lbs and you are only pulling 65 something is WAY out of whack. Get that taken care of first.

When building arrows you want the spine to match your set-up. When you start playing with specs and components you are changing the spine.

These variables cause more flex in the arrow: increase point weight, decreased nock end weight, longer arrow, softer spine arrow, increased poundage, increased draw length

These variables make it flex less (stiffer): decreased point weight, increased nock end weight, shorter arrow, decrease poundage, decreased draw length.

So if I add significant point weight to an arrow making it flex more I then need to change another variable to make it flex less so it stays at my correct spine.

You want the spine of the arrow to match your bow so you have the best accuracy possible.

So play with arrow spine and arrow length to get it to match your set-up. You could go to a 350 shaft cut it a little shorter and this might give you the perfect weight, speed, spine and FOC you want.

AAE max stealth vanes only weight 7.5 grns

What bow do you shoot? this effects what spine you need because of cam/bow design

i am shooting the 31.5 VXR. It still has the original zebra strings on it and I was told this is what is causing the low poundage, because they stretch (limbs bolts are tight). I had planned to replace the strings after the season as I've only had this bow 6 weeks now, and wanted to get some more use out of them, but if it's a problem, I'll make it a priority.

I got the vein weight from the Lancaster website. I thought they were kind of heavy...

Where would I find a program that would tell me arrow spine based on length and component weight?

 

[5 shot group]

If you stay at 65 lbs

go 350 rampage with 100 grain point, 75 grain insert/collar 26" total length with nocturnal
Total weight - 432grains speed -~270 fps FOC- 15%
This spines perfect for 65lbs on software program

If you move to 70 lbs
go 300 rampage 100 grain point 75-grain insert/collar 27.5" length with nocturnal
TAW - 458. Speed ~276. FOC - 14.4%
This spines slightly stiff.

Both of those above options spine nicely and give good FOC.

If you shoot the 300 at 65 lbs it will be a stiff arrow at the heavy point weight and EXTREMELY stiff at the lighter point weights.

What program are you using? It sounds like something I should play with.

 

[MattB]

Curious why you think the heavy one won't spin (stabilize?)? Do you think a 300 spine is too light?

Spine. 200 grs. on the front end is a lot for an arrow of that deflection at that length. Figure out the front end components that get you in the right dynamic spine range with that arrow.

 

[Jimbob]

The software is fun but not needed. If you want to geek out and play with every variable and see what it does to your arrow then ya go for the software


https://www.pinwheelsoftware.com/index.html

 

[5 shot group]

That program is pretty cool. It really shows how things impact spine and let's you tinker with setups to see where the sweet spot it.

I assume the more "matched" you are to your spine the better the arrows will tune/group?

 

[Reburn]

i am shooting the 31.5 VXR. It still has the original zebra strings on it and I was told this is what is causing the low poundage, because they stretch (limbs bolts are tight). I had planned to replace the strings after the season as I've only had this bow 6 weeks now, and wanted to get some more use out of them, but if it's a problem, I'll make it a priority.

I got the vein weight from the Lancaster website. I thought they were kind of heavy...

Where would I find a program that would tell me arrow spine based on length and component weight?

Your bow is out of spec if your only pulling 65 lbs with 70 lb mods. 5 lbs to string strech is complete BS. If the pro shop told you that talk to the owner or find another shop. Its not that hard to put a bow back to spec. I just did it with a rx3 that was so far out of time I could almost stick my pinky between the cable and the stop when the top cam was hitting. After I was done ATA, brace and pull weight were spot on. But you have to have a bow press to add and subtract twists. If you don't know how let a shop do it.

 

[Gorp2007]

I’m doing the same thing you are, trying to settle on an arrow for this fall (debating 450, 475, or 500). If you’re shooting a VXR and Iron Wills, I’m going to assume you’re not missing mortgage payments, so my recommendation is to just build up a few with the two different inserts then use 100 and 125 gr field points and see which ones you shoot best. Use hot melt and you can remove the inserts if you want. Or just use the ones you don’t pick as dedicated small game arrows.

 

[5 shot group]

I’m doing the same thing you are, trying to settle on an arrow for this fall (debating 450, 475, or 500). If you’re shooting a VXR and Iron Wills, I’m going to assume you’re not missing mortgage payments, so my recommendation is to just build up a few with the two different inserts then use 100 and 125 gr field points and see which ones you shoot best. Use hot melt and you can remove the inserts if you want. Or just use the ones you don’t pick as dedicated small game arrows.

I had been saving for a nice spotting scope for a while now and decided the money would be better spent on increasing opportunity. I think the archery stuff will be taking my spotter allowance for a while now though.

I do like the idea of trying the different inserts with hot melt. I love tinkering and think that will be a fun experiment.

But first, I think I need to figure out my draw weight issue. I just checked my mods, and they are the 70lb ones.