[dla]

I've used Beman carbon 15/64 arrows (Hawk and Hunter) with glue-on components for a long time. But my stock of arrows and broadheads was raided by my son, so I purchased some Beman ICS camo hunter arrows. Using the same target, I discovered that the penetration of the ICS Camo arrows is half that of the older 15/64 carbons.

I was kindof dissapointed. One of the reasons I don't use Aluminium is that I loved the penetration of the older, skinny carbons (My son put an skinny carbon arrow diagonally stem to stern through an Elk - that's penetration!). So I'm wondering now just how much penetration I've given up. Any views on this?

 

[BrianMaguire]

I've used Beman carbon 15/64 arrows (Hawk and Hunter) with glue-on components for a long time. But my stock of arrows and broadheads was raided by my son, so I purchased some Beman ICS camo hunter arrows. Using the same target, I discovered that the penetration of the ICS Camo arrows is half that of the older 15/64 carbons.

I was kindof dissapointed. One of the reasons I don't use Aluminium is that I loved the penetration of the older, skinny carbons (My son put an skinny carbon arrow diagonally stem to stern through an Elk - that's penetration!). So I'm wondering now just how much penetration I've given up. Any views on this?

Is it a mass difference? The shaft itself should not make that much difference, there is not that much friction. The big thing is the energy in the arrow. E=1/2M(VV) vsquared=(VV). the energy is mainly in the speed of the arrow but the mass also plays an important role. what are the main differences? What are the different speeds?

 

[dla]

Is it a mass difference? The shaft itself should not make that much difference, there is not that much friction. The big thing is the energy in the arrow. E=1/2M(VV) vsquared=(VV). the energy is mainly in the speed of the arrow but the mass also plays an important role. what are the main differences? What are the different speeds?

Good point. I'll weigh one and put a few over the Chrony and let you know. My guess is that the new ICS are a little lighter than the Older 15/64 Bemans.

However I disagree on the effect of shaft diameter. I have shot too many into targets. And broadheads are a wash. I've not shot a critter with the new ICS, so I don't know the penetration difference on flesh, but I suspect that flesh reacts somewhat like my target.

 

[BrianMaguire]

Good point. I'll weigh one and put a few over the Chrony and let you know. My guess is that the new ICS are a little lighter than the Older 15/64 Bemans.

However I disagree on the effect of shaft diameter. I have shot too many into targets. And broadheads are a wash. I've not shot a critter with the new ICS, so I don't know the penetration difference on flesh, but I suspect that flesh reacts somewhat like my target.

the one thing I was thinking may play a part that is hard if not impossible to measure would be the stiffness. If a shaft its not too stiff it will bend and that will throw off the center of force and make the arrow go in at an angle. You see this with not really true arrows. Some say that carbons never get out of true and that is plain false. carbons can and do get out of true all the time. I have a bucket full of them for the nay sayers. My theory is that if you have a weaker shaft you have bending on impact and that causes more friction and the force going in direction you don't want.

 

[bait boy]

Its been a while since I shot, and posted over here.. but, its the diameter of the arrow that was giving you your penetration. For the same arrow weight having a shaft that is the same diameter as the broadhead provides a friction bearing surface that goes the length of the arrow. the skinny bemans have the same diameter head as a normal broad head (I think) but the shaft is smaller in diameter than the arrow head. The head provides the larger tunnel for the arrow to simply pass through.

 

[dla]

Does anybody know why Beman, now Eastman, went backwards to using fat shafts? I am assuming there were some advantages that offset the loss of penetration.

 

[dla]

Gathered a little data. Both arrows Finished length 30.5", 4" plastic fletch, 100gr tip, spine is 75/85 for old carbon and ICS 300 for new.
Old-style Beman Carbon:

• 419gr
• 245fps
• 0.241" shaft diameter

Beman ICS Camo Hunter:

• 481gr
• 232fps
• 0.305" shaft diameter

So although the speed went down by 5.3%, the momentum increased by 8.7%, KE increased by 3%, yet the penetration decreased significantly. Decrease in penetration is due to shaft diameter increase and perhaps the camo finish.

Summary: skinny carbons rule!