What single bevel design has the most aggressive spiral wounds?

Tee Bone · May 11, 2018, 08:18:39 AM

oops, guess I will have to do some research to figure out how to load this video.

Blessed One · May 11, 2018, 07:18:34 PM

I saw that video and it was impressive just need them heavier for my set up.

JimB · May 15, 2018, 01:15:47 AM

I believe the thickness of the blade and bevel has more influence.

Tajue17 · June 06, 2018, 06:59:16 PM

Abowyer spins pretty quick at impact but I would think it doesn't really matter

ozy clint · June 07, 2018, 07:33:48 AM

i was thinking today about the effect of what is termed 'blade pitch distribution'. pitch distribution is the change in pitch along the length of a propeller blade. closer to the rotational axis the blade has a higher pitch because it doesn't travel as far per rotation than the tips of the blade where the pitch is less. this allows the blade to create more equal thrust along any given point of it's length.

transfer this principle to broadheads and you soon realize that broadheads don't have any change in pitch distribution between the part of the blade close to the rotational axis (the tip of the broadhead) and the part furthest from the axis (the rear of the blade at it's widest point)

whether this is a good or bad thing i'm not sure. it would be bad for a propeller meant to create thrust from rotational energy (aircraft and boat propellers) and a turbine meant to create rotational energy from thrust (steam turbine) as it would be very inefficient.

i was thinking perhaps it is a good thing since when a BH is passing through flesh the wider part of the blade would have greatest effect on the speed of rotation meaning the tip of the blade would effectively be spinning faster than the pitch (bevel angle) would otherwise cause it to rotate. this perhaps creates tension on the flesh passing over the blade edge allowing the edge to cut it more easily.

just some thoughts i had...............

JohnV · June 07, 2018, 09:02:59 AM

I shoot Abowyer single bevel heads and like them a lot. I think width probably contributes the most towards the spiraling effect. Most broadheads have ground edges that are about the same angle so I would think the difference there would be minimal.

JimB · June 07, 2018, 11:24:16 AM

Quote from: MnFn on May 06, 2018, 11:36:57 AM
I think penetration.

Actually,that's exactly what doesn't happen.That's been tested to death.The spreading of the soft tissues by the bevels,evidently relieves pressure and allows the arrow to penetrate better.That's why in Doc Ashby's tests,identical broadheads,one with double bevel and the other single bevel,the single bevel penetrated substantially farther.That's the whole point.

I've used a couple different single bevels but of similar dimensions.In a consistent target medium,they turn,1/4 turn in 4",consistently.Doc Ashby talks about a full turn in 16".That seems to be what I'm seeing.I've only shot a few head of big game with them but wound channels for a 1 3/16" broadhead were 2" wide,in soft tissue.

I'm not sure you will see a lot of difference in rate of twist among different single bevel broadheads.I personally like to use broadheads that are of a 3 to 1 ratio,when I can,to also help with penetration.

89redtruck · June 07, 2018, 03:16:22 PM

If I knew how to post pictures I would show you what a single bevel can do to a deer thigh bone shot from a 46 lb long bow. I was waiting for her to look the other way before shooting when she raised her hind leg to scratch her head. The shot went thru her body and into that raised leg. What it did to that leg was amazing & sold me on single bevels. I couldn't believe what I saw when I started butchering the deer.

Jim