31
Arrows / Re: Poplar arrows
« Last post by Doug509 on December 29, 2025, 11:29:09 am » arrows turned out quite nice. Maybe the forum membership is ready for another arrow exchange this winter.
Recent Posts
32
Bows / Re: Birch bark backing
« Last post by Doug509 on December 29, 2025, 11:19:21 am »Chumash thanks for sharing your birch and cherry bark projects. Its pretty amazing material. I still want to make a pukko knife with a stacked birch bark handle. I finished backing the Yew bow with 0.5mm thick bark. I put a layer of hide glue on the bark let it dry. I glued the bark to the limb tips and knock area first to anchor the bark strip on one limb.
Once dried, a layer of hide glue to adhere the rest of the bark from knock to handle. Quickly wrapped with compression bandage then glued up the other limb. It turned out really nice. I just have to clean up the edges wil sand paper and let it dry for a couple weeks.
Once dried, a layer of hide glue to adhere the rest of the bark from knock to handle. Quickly wrapped with compression bandage then glued up the other limb. It turned out really nice. I just have to clean up the edges wil sand paper and let it dry for a couple weeks.
34
Bows / Re: Birch bark backing
« Last post by medicinewheel on December 29, 2025, 02:58:19 am »Andy, is that you?
35
Bows / Re: Bamboo-maple-horn, 98#@28"
« Last post by Badger on December 29, 2025, 01:15:23 am » There is no debate because we don't know how much energy the bow stores; we can only guess at this point. Using virtual mass to predict arrow speed is not debatable; it has been used for decades. Now, just for fun, if he shot, say a 700-grain arrow and then let us guess the speed of the 320 it would be fun. I thought you said 350, I will go back and figure it at 320 with 160 grains VM and see what it comes to.
Ok my official guess is 292
Ok my official guess is 292
36
Bows / Re: Bamboo-maple-horn, 98#@28"
« Last post by sleek on December 29, 2025, 12:13:33 am »I chronoed this bow. With a light 463 grain arrow (about 5 gn/#) the result was 256 fps. Quite ok, I am happy. Shot with a shooting machine, witnessed by my friend.
Do you mind solving a debate and making a 320 grain arrow to chronograph?
37
Bows / Re: Bamboo-maple-horn, 98#@28"
« Last post by Badger on December 29, 2025, 12:05:59 am » You are wrong the best predictor of speed over an assortment of different weight arrows is virtual mass, which is based on stored energy and efficiency. The lower the virtual mass the less drop in ke as arrows get lighter.
I would guess that this bow probably stores about 93% or in that area. In that case his virtual mass would be lower and his arrow speed might be closer to 300.
I would guess that this bow probably stores about 93% or in that area. In that case his virtual mass would be lower and his arrow speed might be closer to 300.
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Bows / Re: Bamboo-maple-horn, 98#@28"
« Last post by mmattockx on December 28, 2025, 11:56:48 pm »If he is storing 100% of draw force it would put his virtual mass at about 200 grains. Giving him around 285 for 350 grains. If he is storing less energy he would have a lower VM and have a higher speed.
It doesn't matter how much energy is stored because it is the same for both arrows. To get the velocity for the 320gr arrow you simply equate the kinetic energy of both arrows and solve for the velocity of the lighter arrow. That assumes the efficiency stays constant, which it likely doesn't, so the lighter arrow won't quite get to the calculated speed.
Mark
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Bows / Re: Bamboo-maple-horn, 98#@28"
« Last post by Badger on December 28, 2025, 01:39:06 pm »If he is storing 100% of draw force it would put his virtual mass at about 200 grains. Giving him around 285 for 350 grains. If he is storing less energy he would have a lower VM and have a higher speed.
40
Bows / Re: Bamboo-maple-horn, 98#@28"
« Last post by mmattockx on December 28, 2025, 01:22:19 pm »256fps is certainly on the HOT side of things. Thats fast! Especially with a 460 grain arrow. Id like to see what it will do with a 320 grain arrow.Based off of energy storage the 320gr arrow will go ~308fps if the bow efficiency stays the same. It will likely drop a bit with the lighter arrow, so figure on a bit less.
Mark