Why Magnus is not making a single bevel tanto tip head - Page 2 -

Outbakbowhunter · 05-07-2010, 06:42 PM

Quote:

Originally Posted by top dog rick

Makes sense How many single bevel Ax's have you seen ?

not many single bevel hunting knives I know of !

Also all of the single bevel's I have seen are steel .

How would Stainless hold up to single bevel ?

No axes, but when sugar cane was harvested by hand, the cane knives were single bevel, and their are many examples of single bevel knives.

A lot of Japanese kitchen knives are single bevel. This is because the achieve super sharp from lower edge angles and are ideal for slicing tasks.

But what makes a good knife does not always work on broadheads, as I have said before, it's my opinion an edge bevel under 30 degrees is not strong enough for a broadhead edge, in the 125 grain weight class.

Stainless steel is just steel with more chrome content, apart from rust resistance, it offers no real advantage to broadhead working performance.

It does make extra problems with heat treating, and the extra expense involved to make ss heads makes them more expensive for bowhunters to buy.

I have also seen pictures of knapped single bevel Clovis obsidian atyl atyl heads, so single bevel designs have been around for a awhile.....

WoodySanford · 05-08-2010, 11:51 AM

Quote:

Originally Posted by Outbakbowhunter

Woody,
You said above that
"The single bevel causes a significant reduction in volume of the edge, "

I am not sure that I agree with that. What is the bevel angle you are talking about.

Is not the bevel angle adjustable by manufacturer to be as low or high an angle as desired.

Why cant a single bevel be made at a higher angle for better edge retention strength.

I dont agree with Ed Ashby on his lower edge bevel angles, ( from memory about 15 degress) but personally I like an edge angle of 30 degrees or higher.

Ed's opinions are mainly geared for uber broadheads on very big game, but some of his ideas are good (with a little tweaking) for guys shooting 125 grain models.

I dont really think single or double bevel makes that big a difference on deer sized game, if both styles are razor sharp and both are routinely giving pass throughs, the game is no more or no less dead.

I like them, because they are easier to sharpen, and I believe they also have a slight edge in accuracy ( I think they also spin more in flight ) as in tighter groups.

I hope to save up and get a Hooter Shooter before the end of the year, which will either prove or disprove it.

On comparing the volume of mass in both a single and double bevel I use the average of what is available on the market. In other words what is out there for us to get our hands on. I can lower the angle and have but the problem is to increase the volume of material to equal that of a double, it would be so low that it will not slice well and creates a surface that will push tissue.

There is a significant difference in edge quality between a stainless and carbon steel at the same hardness, especially in regards to retention. I don't see any influence on accuracy between the different bevels at all. I've also tried to film the theoretical spinning of the single bevel through an animal carcass with high speed video and don't see it acting any different than a double. They will both take direction from bone and the single will sometimes rotate counter to the direction it is supposed to from that.

If a blade is made from good steel and made correctly, 20 degrees isn't bad at all on a double bevel. Cut that in half length wise and you have a 20 degree single with a significant reduction in volume and edge retention. I prefer to be in the area of 22-25 degrees when I resharpen a blade depending on the steel. 30 is still good but passing 30 and you are getting in the area of creating a surfact that will push tissue.

Outbakbowhunter · 05-09-2010, 08:17 PM

Quote:

Originally Posted by WoodySanford

On comparing the volume of mass in both a single and double bevel I use the average of what is available on the market. In other words what is out there for us to get our hands on. I can lower the angle and have but the problem is to increase the volume of material to equal that of a double, it would be so low that it will not slice well and creates a surface that will push tissue.

There is a significant difference in edge quality between a stainless and carbon steel at the same hardness, especially in regards to retention. I don't see any influence on accuracy between the different bevels at all. I've also tried to film the theoretical spinning of the single bevel through an animal carcass with high speed video and don't see it acting any different than a double. They will both take direction from bone and the single will sometimes rotate counter to the direction it is supposed to from that.

If a blade is made from good steel and made correctly, 20 degrees isn't bad at all on a double bevel. Cut that in half length wise and you have a 20 degree single with a significant reduction in volume and edge retention. I prefer to be in the area of 22-25 degrees when I resharpen a blade depending on the steel. 30 is still good but passing 30 and you are getting in the area of creating a surfact that will push tissue.

Woody,
I beg to differ, a double bevel broadhead with 20 degree bevel angles on each side of the blade, has a combined angle of 40 degress. ( 20 X 2 = 40 ) and we all consider that a good angle for sharp.

A single bevel angle is what it is. What ever the broadhead maker sets it to be.

I believe that single bevel edges are plenty strong enough, as long as they are made at no less an angle than 30 degrees angle of bevel.

Which is still significantly sharper than your example of the 20 degree double bevel. (20 X 2 = 40 degrees )

I also disagree about the twisting cutting motion that single bevel edges give.

If they dont twist, as you say, how is it that all the photo's of s shaped entry wound pictures, of single bevel heads, are shown on bowhunting forums, when ever the single bevel broadhead style is discussed.

Either you are mistaken on that point, there is another explanation for them, or there are one hell of a lot of photo shopped photos circulating out their with a pro single bevel broadhead agenda.

I mentioned in an earlier post, that I dont think a single bevel makes all that much difference on deer sized game, double bevel heads are still working just as good as they always did, so dont misunderstand me, I am not advocating single bevels to the exclusion of all others.

I personally like them because I find them very easy to sharpen, and I do think they have a very small edge in accuracy ( tighter groups ) especially as the range get out to 50 yards or more.

I have had quite a few guys say this to me, its not just my single idea, but when I can afford one I would really like to buy a hooter shooter to ascertain whether or not its just my misguided opinion or a prove-able fact.

It is true that most commercial single bevel style heads in the US, are made with very low angles, which can work if the blades thickness is enough to allow higher tempered hardness values for edge retention.

I think this works on the 200 + grain heads if you are going on a safari in Africa, but in the 125 grain weight class broadhead for average day to day hunting, a 30 degree bevel angle on 1055 spring steel blades, about 50 Rockwell hardness is about right.

Ultimately, the commercial success of any particular broadhead style, over the long term, depends on whether it works.

If a thing is a lemon you will only get one purchase per customer, they return for more only if they are happy with its performance.

Whether or not they are your "cup of tea" I do think single bevels are here to stay.......

WoodySanford · 05-10-2010, 09:18 AM

Quote:

Originally Posted by Outbakbowhunter

Woody,
I beg to differ, a double bevel broadhead with 20 degree bevel angles on each side of the blade, has a combined angle of 40 degress. ( 20 X 2 = 40 ) and we all consider that a good angle for sharp.

A single bevel angle is what it is. What ever the broadhead maker sets it to be.

I believe that single bevel edges are plenty strong enough, as long as they are made at no less an angle than 30 degrees angle of bevel.

Which is still significantly sharper than your example of the 20 degree double bevel. (20 X 2 = 40 degrees )

I also disagree about the twisting cutting motion that single bevel edges give.

If they dont twist, as you say, how is it that all the photo's of s shaped entry wound pictures, of single bevel heads, are shown on bowhunting forums, when ever the single bevel broadhead style is discussed.

Either you are mistaken on that point, there is another explanation for them, or there are one hell of a lot of photo shopped photos circulating out their with a pro single bevel broadhead agenda.

I mentioned in an earlier post, that I dont think a single bevel makes all that much difference on deer sized game, double bevel heads are still working just as good as they always did, so dont misunderstand me, I am not advocating single bevels to the exclusion of all others.

I personally like them because I find them very easy to sharpen, and I do think they have a very small edge in accuracy ( tighter groups ) especially as the range get out to 50 yards or more.

I have had quite a few guys say this to me, its not just my single idea, but when I can afford one I would really like to buy a hooter shooter to ascertain whether or not its just my misguided opinion or a prove-able fact.

It is true that most commercial single bevel style heads in the US, are made with very low angles, which can work if the blades thickness is enough to allow higher tempered hardness values for edge retention.

I think this works on the 200 + grain heads if you are going on a safari in Africa, but in the 125 grain weight class broadhead for average day to day hunting, a 30 degree bevel angle on 1055 spring steel blades, about 50 Rockwell hardness is about right.

Ultimately, the commercial success of any particular broadhead style, over the long term, depends on whether it works.

If a thing is a lemon you will only get one purchase per customer, they return for more only if they are happy with its performance.

Whether or not they are your "cup of tea" I do think single bevels are here to stay.......

Angle isn't the only thing that contributes to sharpness. Most single bevels are at a lesser angle than 30 degrees and suffer a greater loss of edge retention just as I wrote in the begining and in the article. I just reported that from what I actually saw while testing on carcasses from NC whitetails to AK moose. I also observed the inconsistency of the rotation through carcasses by use of a high speed video camera. They will turn counter to their suggested rotation as deemed by the bevel. I will be putting that video up on my website eventually along with microscope pictures of damage to the edge in comparision to a double going through the same area of a carcass.

From what I see first hand, the tip has more influence than the bevel on the blade but the larger you make the tip the less efficient it is. The more it will increase directions on impact, push bone and stretch hide, exhausting energy. I personally don't see the need for such large tips on any NA game or SA for that matter, its more eficient to strengthen by blade thickness for volume than geometry. Since most use heavier heads for such game it is more suitable.

Like what you like, doesn't really matter to me. I don't see the benefit as claimed to the single bevel or the need to re-invent the wheel. If the benefit was as obvious as some claim we would use it. Its definately easier to manufacture and would speed up run times on grinding heads, which equals more money but the benefits of the double bevel outweigh it on our line.

I believe the majority of the "S" wounds you see in hide are from the tip extending hide beyond its limits, rupturing it or trying to force its way through and wrapping it up. The rotation isn't consistent in wound tract survey's.

Outbakbowhunter · 05-10-2010, 12:07 PM

Woody,
I dont remember mentioning anything about the size of the tanto tips I like on my broadheads,.... for what its worth the tanto style tips as used on Magnus heads look about right to me, so we are not disagreeing on that point......lol

I am saying that I also think bevel angles under 30 degrees do not make an edge sturdy enough to hold up without problems with bone hits.

The bevel angles you are not happy with, are mostly around the 15 degrees, and I agree that this is too fine an edge to be strong enough .

All I am suggesting, should Magnus ever consider doing one, is to not follow the crowd, and grind your own higher bevel angle that is much stronger.

The s shaped entry wounds are an interesting feature, what ever the reasons for them, you have to admit they are cutting a wider total slit in the hide than just a strait slit entry.

Surely that must have some advantage for laying down a better blood trail.

When Ed Ashby was doing research on single bevels, I was happy to supply some broadhead samples for him to play with.

Identical models, except for right wing, left wing and double bevels, the measured differences in penetration he published in his research were certainly thought provoking.

Can you refer me to a link to your videos of single bevel at work, because I would very much like to see different takes and opinions on the topic, and it is possible I may learn something.

WoodySanford · 05-10-2010, 03:03 PM

Quote:

Originally Posted by Outbakbowhunter

Woody,
I dont remember mentioning anything about the size of the tanto tips I like on my broadheads,.... for what its worth the tanto style tips as used on Magnus heads look about right to me, so we are not disagreeing on that point......lol

I am saying that I also think bevel angles under 30 degrees do not make an edge sturdy enough to hold up without problems with bone hits.

The bevel angles you are not happy with, are mostly around the 15 degrees, and I agree that this is too fine an edge to be strong enough .

All I am suggesting, should Magnus ever consider doing one, is to not follow the crowd, and grind your own higher bevel angle that is much stronger.

The s shaped entry wounds are an interesting feature, what ever the reasons for them, you have to admit they are cutting a wider total slit in the hide than just a strait slit entry.

Surely that must have some advantage for laying down a better blood trail.

When Ed Ashby was doing research on single bevels, I was happy to supply some broadhead samples for him to play with.

Identical models, except for right wing, left wing and double bevels, the measured differences in penetration he published in his research were certainly thought provoking.

Can you refer me to a link to your videos of single bevel at work, because I would very much like to see different takes and opinions on the topic, and it is possible I may learn something.

I haven't got them on my site yet or the site up. Its close but with work and two little ones (my boy being born this March) I'm running about two months behind on it. I'm about to start depredation killing of whitetails but will get it up and get the info on there as fast as I can. Writing seems to take me a while.

Outbakbowhunter · 05-10-2010, 06:51 PM

Family and hunting come first, when you can find the time to post them up, I will look forward to seeing your video clips,

good hunting,

Outbackbowhunter.

wyetterp · 09-06-2010, 11:05 AM

Quote:

Originally Posted by WoodySanford

I haven't got them on my site yet or the site up. Its close but with work and two little ones (my boy being born this March) I'm running about two months behind on it. I'm about to start depredation killing of whitetails but will get it up and get the info on there as fast as I can. Writing seems to take me a while.

Is the site up yet? If so where would I find it? If not I can't wait to gain from your test & knowledge.

Thanks Woody!

WoodySanford · 09-06-2010, 12:58 PM

Quote:

Originally Posted by wyetterp

Is the site up yet? If so where would I find it? If not I can't wait to gain from your test & knowledge.

Thanks Woody!

Its up but there is nothing on it yet. Its woodworksmedia.com

I'm swamped at work and have the two little kids. I haven't had the time to work on it. I'm about to start field work for the season and that actually gives me much more free time. During the off season I don't just handle R&D but also product production issues, video, commercials, the company website, graphics, print ad's, the catalog and answer many tech calls every day, so its a full boat seven days a week and any down time is spent playing Dad.

It will come.

wyetterp · 09-06-2010, 02:31 PM

Bookmarked! Thanks

Konrad · 10-10-2010, 01:49 AM

Much of what you have written explains why the Slick Tricks go whack when they hit the animal and the Stingers go whack when they hit the brush on the other side of the animal.

This is the ‘meat” I seek on sites like this.

The Ashby tests are primarily based on the “Modified Grizzly”. It has only a seven eights inch maximum width (which harkens back to your comment about small cutting diameters required for edge support) and the three to one width to length ratio.

Question: Has there ever been quantitative study on ballistic coefficients or aerodynamic drag of broadheads?

Thanks,
K

WoodySanford · 10-10-2010, 05:58 PM

Quote:

Originally Posted by Konrad

Question: Has there ever been quantitative study on ballistic coefficients or aerodynamic drag of broadheads?

Thanks,
K

Not to my knowledge. Given the many that are out there it would be one heck of a large project.

09-06-2010, 02:31 PM	#25 (permalink)
wyetterp 100gr Join Date: Mar 2010 Location: Murrells Inlet, SC Posts: 204	Bookmarked! Thanks __________________ *Experience is something you don't get until just after you need it.*

10-10-2010, 01:49 AM	#26 (permalink)
Konrad 75gr Join Date: Oct 2010 Location: Western Washington State, almost to Canada Posts: 22	Much of what you have written explains why the Slick Tricks go whack when they hit the animal and the Stingers go whack when they hit the brush on the other side of the animal. This is the ‘meat” I seek on sites like this. The Ashby tests are primarily based on the “Modified Grizzly”. It has only a seven eights inch maximum width (which harkens back to your comment about small cutting diameters required for edge support) and the three to one width to length ratio. Question: Has there ever been quantitative study on ballistic coefficients or aerodynamic drag of broadheads? Thanks, K __________________ The Constitution is Not a Suicide Pact Eschew Obfuscation

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05-10-2010, 12:07 PM	#20 (permalink)
Outbakbowhunter Trial Member Join Date: May 2010 Posts: 9	Woody, I dont remember mentioning anything about the size of the tanto tips I like on my broadheads,.... for what its worth the tanto style tips as used on Magnus heads look about right to me, so we are not disagreeing on that point......lol I am saying that I also think bevel angles under 30 degrees do not make an edge sturdy enough to hold up without problems with bone hits. The bevel angles you are not happy with, are mostly around the 15 degrees, and I agree that this is too fine an edge to be strong enough . All I am suggesting, should Magnus ever consider doing one, is to not follow the crowd, and grind your own higher bevel angle that is much stronger. The s shaped entry wounds are an interesting feature, what ever the reasons for them, you have to admit they are cutting a wider total slit in the hide than just a strait slit entry. Surely that must have some advantage for laying down a better blood trail. When Ed Ashby was doing research on single bevels, I was happy to supply some broadhead samples for him to play with. Identical models, except for right wing, left wing and double bevels, the measured differences in penetration he published in his research were certainly thought provoking. Can you refer me to a link to your videos of single bevel at work, because I would very much like to see different takes and opinions on the topic, and it is possible I may learn something.

05-10-2010, 06:51 PM	#22 (permalink)
Outbakbowhunter Trial Member Join Date: May 2010 Posts: 9	Family and hunting come first, when you can find the time to post them up, I will look forward to seeing your video clips, good hunting, Outbackbowhunter.