3 to 1 ratio broadheads - what's the deal

[Jake Diebolt]

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.

[Owlmagnet]

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.

[SlowBowke]

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

[SlowBowke]

Ya beat me, Owl! Thanks for the confirmation.

God Bless

[Ragnarok Forge]

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.

[snag]

I have always found that the 3:1 head is a great flying head also.

[Owlmagnet]

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....

[Jake Diebolt]

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.

[Owlmagnet]

My pleasure, Jake!

[Tree Rat]

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.

[Spectre]

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.

[Bjorn]

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.

[Bjorn]

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.

[Running Buck]

The longer taper provides a higher mechanical advantage. Kind of like the difference between a filet knife and a butcher knife.

[JamesKerr]

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.

[SlowBowinMO]

I find the longer, leaner heads tend to fly exceptionally well too.

[Adam Keiper]

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.

[Flingblade]

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.

[JimB]

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.

[owlbait]

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.