I've always wondered why people quote the '3 to 1 ratio' as ideal for broadheads. Is it the result of studies done on penetration, or is it just a ratio that has been found to maximize penetration in the field? or is it considered a happy medium between cutting width and penetration?
The Woodsman marketers seem to push the concept pretty strongly (I use woodsmans myself, like them so far), but I was just wondering where the whole idea came from.
In his book, "Hunting The Hard Way", Howard Hill strongly asserts: "To secure the maximum penetration in shooting game, each broadhead should invariably be so constructed that it is three times as long as it is wide. The cutting angle will then be in the proper proportion to the rest of the head. The use of proportions as just given will also help the flying qualities of the arrow."
Now, this was Mr. Hill's opinion, but agree or disagree, it was an INFORMED opinion!!! I hope that is useful, Jake.
Unless it is a "preferred" memory,and very well could be, I think Howard Hill was the culprit in charge of that relationship being so accepted and was from his hunting experiences.
Someone hammer me if wrong but what I've always thought.
God Bless
Ya beat me, Owl! Thanks for the confirmation.
God Bless
Penetration is the main reason for 3 to 1. It is important to note that a true 3 to 1 as defined by Mr. Hill was for a two blade head.
I have always found that the 3:1 head is a great flying head also.
The thing is, Slowbowke, I wonder if Mr. Hill was inspired by the advice of Saxton Pope. In his book, "Hunting With The Bow And Arrow", Pope says: "...we shoot a head whose blade is three inches long, an inch and a quarter wide,..." He goes on to advise: "The heads, if found too broad for perfect flight, should be ground a trifle narrower." Another very informed opinion. At this point, we are getting very, very close to the 3 to 1 ratio....
It does seem like a logical set of dimensions - wide enough to cause significant bleeding on penetration, narrow enough so that the blade has an easy time going through.
Lately I've been thinking a lot about broadheads - I've been reading through the Dr. Ashby reports archived here - and it struck me that I'd accepted the 3 to 1 ratio as good for a broadhead without even investigating the source. I thought, if only there were a forum of knowledgeable bowhunters where I could go for advice...oh wait! There's one right here!
Thanks for the replies guys.
My pleasure, Jake!
I read the reasoning behind this years ago and it has nothing to do with any of the archery heroes.
Its basic physics. (I don't know the exact wording) A broadhead is a mechanical incline. The most effective angle for an incline is 3:1.
I truly believe that they can and will penetrate better than the steeper designs, however, I am a durability guy. I do like some of the short, fat heads for that reason. RFA comes to mind.
Howard gets the credit........In Hunting the Hard Way.........pg 120, 121, he describes how to make his BH exactly 3:1 for optimal penetration.
Howard gets the credit........In Hunting the Hard Way.........pg 120, 121, he describes how to make his BH exactly 3:1 for optimal penetration.
The longer taper provides a higher mechanical advantage. Kind of like the difference between a filet knife and a butcher knife.
I think it is important to remember that even though a multiblade head may be 3 times as long as it is wide it is still not a true 3:1 ratio as most 3 bladed broadheads that claim the 3 to 1 ratio only have a mechanical advantage of 1.5 or so while a 3 to 1 2 blade head has a ma of 3.0. This is not to say that a multiblade head is better or worse than a 2 blade. I myself prefer a long narrow 3 blade for most of my hunting as it gives me plenty of penetration with optimal blood trails.
I find the longer, leaner heads tend to fly exceptionally well too.
The shallower the blade angle, the better cutting capability a blade has. Beyond 3:1 though, the blade tip becomes too delicate and starts to become prone to bending or folding. So 3:1 has long been deemed optimum. Long enough for great cutting/penetrating qualities, yet short enough to remain very rugged.
The next question would be if the 3:1 ratio is agreed to be superior why are there so few 3:1 two blades on the market? I recently switched to the 175 grain Simmons Tiger Shark. I think the concave cutting design was also preferred by Mr. Hill and changes the game again.
There are a couple reasons you don't see more 3:1 ratio broadheads.
Some states have a legal limit of 1" for broadhead width.If it were 3:1,it would be 3" long.That doesn't fit many bow quiver hoods and many people want a wider broadhead.
Make the broadhead 1 1/4" wide and you now have a broadhead 3 3/4" long and a lot heavier than many people like.
For decades 125 gr broadheads were the accepted norm and many people still prefer that.Making a 3:1 broadhead that will meet most states minimum width requirements even after sharpening,and keeping a decent blade thickness for strength,means heavier heads.Some like that.Many don't.
Even the Ashby heads and Grizzly El Grandes aren't 3:1 ratio.
There was a broadhead at Compton's called the Tuffhead. 225 grain glue on that was long, lean, and mean. Vendor was Vintage Archery from Charleston, Il. Great looking head.
In regards to the lack of longer broadheads, one has to remember that back in the day, almost all broadheads were glue ons that had to have the taper of the shaft glued into it. Nowadays with the screw ins the ferrule of the broadhead can be as short as they want them as the attaching system is screwed into the shaft.
As a kid, we were always taught the 3 to 1 rule. Although I personally think that the 3 to 1 ratio that Hill professed was more for flight characteristics than cutting ability. The curvature of the blade in a hill head is not in any fashion a true 3 to 1 angle. The over all ratio of the heads profile is there but with the convex and concave curves of the blade cover almost any angle you want. JMHO
OWLBAIT, That was Joe Furlong(sp,sorry Joe). And yes it is a very tuff looking head. I will wager that we will see alot of this head in the future. many good features.single beval,tanto tip,stainless steel and some more that you have to see to understand(at least I did).
Thanks Chuck, I knew it was Joe, just didn't remember last name. Great looking head. Too heavy for my equipment I think. He also had the bowtote sling that was a topic of discussion here not long ago. Nice guy too!
There was in fact a study done in the mid 80s ( as I recall ) it was published in one of the BIg Mags at the time .
Jist of the article was that the broad- head either CHOPS or SLICES The ideal between both of these extremes seems to be 3to 1 the more you CHOP ( wider head ) the less penetration you get and start losing flight aerodynamics . The more you reduce width you gain penetration and it flies well but then you start missing arteries and veins and organs by just puncturing the animal hunted . SO three to one seemed to be the best compromise BUT as stated here HILL said it first and he had the back up experience.
I bought couple of packs of those Tuff heads from Joe this weekend. I'm going to experiment with them some and they will probably be the head of choice for our Australian Buff hunt next year.The Ashby head was a contender, but after talking to Joe on his manufacturing process I'm certain his head is better steel and stronger than the Made in China version.
Hunt it
I have not seen the new heads yet but they are on the way. I did some testing with the prototype and did not find them lacking. Joe has kept me in the loop with most of the difficulties of manufacturing. I doubt whether many of the other broadheads can keep up too these standards.I'm sure they will work just fine on Australian Buff's.
Abe
Who wants to shoot (excluding moose, brown bear, and griz) a broadhead that's one inch wide? And for what reason? Today we have 40 pound bows that can cut two holes in any whitetail made.
There are very few 3 to 1 BH's out there. WW is not one, unless you want to be political about the term 3 to 1.
Bowmania
Many heads that are advertised as 3:1 ratio are not. Measure them and see. A true 3:1 is going to be a long head to get a decent cutting width. That is why there are so few on the market although some try to advertise their heads are 3:1 when not. Ed Ashby look at broadhead length/width ratio and how it affected penetration in some of his earlier studies.
3 to 1 might give you a great cutting angle, but it also gives you a very long head that's not only more susceptible to bending or folding, but also puts a ton more leverage against the ferrule on a hit.
You have to overbuild a 3 to 1 head to get good durability.
Well to those that think this is just advertising,this the prototype is just over 1" wide and 3 1/8" long.I do hunt elk ,moose ,deer and turkey. I like the idea of a 3 to 1 head not so much when everything goes right but when the don't. I know this is not for everyone but it is for me. This head is tuff just like the name suggests. Abe
Arrow flight is "easier" these days, so broadhead design was likely more critical as well back when the recommendations were made. We have better materials now, more options, etc. Howard used to grab a bunch of broadhead arrows and shoot a bush (target). The ones that hit he would sharpen, the o es that missed he would shoot one more time and
A recent post had a link to Rocky Mountain Specialty Gear about shooting 2- or 3-blade braodheads. The article is listed under "Tutorials". It lists a formula from Dr. Ashby on how to calculate mechanical advantage (MA). Longer broadheads have a higher MA, which is desirable for penetration.
link to RMSG:
http://www.rmsgear.com/broadhead_debate.html