[Ed Ashby]

in reply to: A Question of Draw Weight #26540

Hello Dave. Probably doing better than I deserve to. The next surgery is scheduled for November 4th.

Ed

[Ed Ashby]

in reply to: EFOC #25431

I not yet sure that there is a point of diminishing returns with EFOC/Ultra-EFOC. Remember that going up in FOC does not always mean going up in arrow weight. As I’ve moved the testing into EFOC/Ultra-EFOC I’ve been able to progressively reduce total arrow mass (on buffalo) while simultaneously maintaining or improving on the penetration demonstrated by substantually heavier, perfectly tuned arrows having the same broadhead, but having normal and/or high FOC.

So far I’ve only been able to test FOC up to the 32% level, but it appears that every benefit of FOC only gets better as the FOC gets higher: Flight gets more stable, less fletching area is required to stabalize the broadhead in flight, paradox recovery gets faster, and the rate of gain in soft tissue penetration, per each percent of FOC increase, gets gereater the higher the arrow’s FOC. (There will be more data coming in the next Update on the degree of progressive rate of penetration gain as FOC get higher.)

As Dave correctly points out, the degree of FOC has no effect on the heavy bone threshold. For breaking heavy bone it’s important to keep the arrow’s mass at or above 650 grains, and that’s assuming you have the other factors in place; TOTAL arrow integrity, perfectly tuned arrow flight and a broadhead with a Mechanical Advantage of 2.6 or more (and “broadhead ratio”, as some use the term, does not always mean same as the MA – don’t confuse the two. There are some popular broadheads being referred to as “3 to 1 ratio” broadheads that have a MA well below 2.0!).

Ed

[Ed Ashby]

in reply to: A Question of Draw Weight #23905

stefan 1984 wrote: i think you can make more mistakes with the joice of the right arrow..

Dr. Ed Ashby wrote: The one overwhelming thing the Study has shown is that arrow design is a far bigger factor in terminal arrow performance in tissues than is the draw weight of the bow. – Ed

Right on, Stefan.

Ed

[Ed Ashby]

in reply to: EFOC #23900

Ireland wrote: Does any company make steel adapters heavier than 125 grains or brass inserts heavier than 100 grains?

Here’s a link to a thread that has the links that take you to a website for heavier, steel inserts.

https://www.tradbow.com/members/cfmbb/messages.cfm?threadid=85901E0D-1422-1DE9-ED2018C61D4B27EA

Ed

[Ed Ashby]

in reply to: Elk Arrows #9045

Looking forward to hearing how they perform on your elk, Mike. What broadhead are you using?

Ed

[Ed Ashby]

in reply to: Just a reminder … #63324

You bet I do, Robin. The more information we can collect the better. Especially needed are the Blood Trail Reports.

Ed

[Ed Ashby]

in reply to: HOW SHARP IS SHARP ENOUGH? #63309

Go get ‘um Dave! What I find so great now is that we (finally)have enough well designed, quality single-bevel broadheads around that it’s getting harder and harder to chose which one is best. That’s a very good ‘problem’ to have!

Ed

[Ed Ashby]

in reply to: HOW SHARP IS SHARP ENOUGH? #63266

jaytbuzzard wrote: I’ll be using my Dad’s Black Widow recurve and his Bear Razorheads, he passed away a few years ago. I can’t wait.

Situations like this are one of the intangable factors that make a hunt something truly special. Hope you nail a monster buck!

Ed

[Ed Ashby]

in reply to: HOW SHARP IS SHARP ENOUGH? #62214

sharpster wrote: Sometimes you can get a knife too sharp for a particular application

The perfect example of a knife ‘too sharp for the job’ is one used for fleshing a hide. The best edge for that job is one that’s a bit ragged and far less than razor sharp. Too sharp and it’s almost a certainty that you will end up cutting through the hide too.

Ed

[Ed Ashby]

in reply to: HOW SHARP IS SHARP ENOUGH? #61288

Wildschwein wrote: What is the ideal level of Rockwell?

The ‘ideal’ hardness varies by the individual type of steel used. Regardless of steel type, I’ve not found any broadhead with a hardness much below R50 that (when ‘truly sharp’ to start with) routinely retains its edge sharpness after penetrating a large animal, even when sharpened at higher sharpening angles.

I think this is why the (relatively) rough, ragged file sharpened edge became popular. When the edge is not actually sharp a ragged edge is more likely to tear the tissues, rather than push them aside. The ragged edge is better than a dull edge, but it is far inferior to a truly sharp edge that retains its sharpness. A small detail that shows a big difference in results.

Most broadhead that are EASILY file sharpened will have a hardness no greater than in the upper 40’s.

Ed

[Ed Ashby]

in reply to: HOW SHARP IS SHARP ENOUGH? #61282

Dave, the Grizzly’s I’ve had hardness tested have run from R52 to R56, with R52-53 being the most common hardness. The ABS Ashby is harder, and that’s definitely noticable when the retained sharpness is tested after penetrating both the on and off side ribs of a buffalo.

Specifications on the ABS Ashby calls for R58 hardness. That not withstanding, the folks at ABS have recently changed the company doing the heat treating on the Ashby BH because they were getting a few heads testing above R62. I’ve tested up to R62, and that was the point where I first started to commonly see small edge chips (which is why the ‘spec’ was set at R58). Above R62 hardness would likely increase the number of chipped edges significantly.

BTW, the ABS Ashby is not a cast head. Each head is individually machined from a solid block of steel.

Ed

[Ed Ashby]

in reply to: 2 Blade double bevel and 3 blade vs single bevel #61238

Brett, now that’s an example that has never crossed my mind!

Ed

[Ed Ashby]

in reply to: Sioux arrow #61149

It’s a pretty safe bet that the broadhead on the arrow shown was a lot better aligned when it was ‘in use’ than it is today. It likely that the shaft has dried and sharnk through the years, losening the broadhead’s bindings and allowing the broadhead to shift alignment. I watched the PNG hunters spin their arrows on the tip, so I KNOW they are switched on the checking ‘broadhead alignment’.

Ed

[Ed Ashby]

in reply to: HOW SHARP IS SHARP ENOUGH? #61145

How low a sharpening angle you can use on a broadhead and still have it retain its sharpness all the way through the course of penetration is a function of the quality and hardness of the steel in the broadhead.

As Sharpster aludes to, an edge can, in theory, be reduced to a single molicule of steel at virtually any sharpening angle, but I also prefer as long a bevel (as low a sharpening angle) as I can use and still have the edge retain its sharpness during penetration.

The edge bevel itself is a simple machine; and inclined plane. The lower the sharpening angle the higher the mechanical advantage (MA) of the edge bevel. The higher the edge bevel’s MA the deeper it slices at any given level of pressure between the edge and the tissues; or one could say it slices equally deep at less tissue pressure than an equally sharp edge having a lower mechanical advantage.

When the broadhead you are using has softer steel you need to have the angle of the edge bevel more abrupt (a steeper sharpening angle) in order to prevent the edge rolling or dulling during the cut, but that sacrifices the edge’s MA.

To put it in simple terms, when an edge bevel with a higher MA barely touches the wall of a vessel it is more likely to cut into the vessel than is an equally sharp edge having a lower MA.

Attention to small details sometimes makes a big difference in outcome. This tiny difference in the broadhead’s edge design can make a big difference on marginal hits.

All that not withstanding, you need to find the correct sharpening angle for the individual broadhead you are using, and that’s why you need to evaluate just how sharp your broadhead is AFTER EACH SHOT you make through the tissues of game. We learn from observing the outcomes.

One more point. While the “ideal edge” will remain totally undamaged and retain its sharpness on each and every shot through tissues; regardless of the tissues hit; it’s FAR better to have a broadhead with steel hard enough that it loses a few small chips from the edge on hard tissue hits than it is to have one with steel so soft the edge dulls, rolls, or, even worse, bends on hard tissue impact.

Ed

[Ed Ashby]

in reply to: HOW SHARP IS SHARP ENOUGH? #60145

Just to add another important factor about ‘how sharp is sharp enough’, not only does your broadhead need to be “truly sharp” when it impacts an animal, it should be just as sharp AFTER it’s penetrated through the animal. If it’s not just as sharp at exit as it was upon entry then the broadhead has lost some of its cutting efficiency at some point during the course of penetration through the tissue(s). This retained sharpness makes the most difference (in recovery rate) on shots through tissue(s) that have few, or fewer, sizable blood vessels, such as stomach, intestival and pure muscle hits.

This is a sharpness factor that I see few bowhunters paying enough attention too, and one that does affect the likelyhood of recovering game on many less-than-perfect hits. Sharpenss retention requires good quality steel in the broadhead, which generally also means a broadhead that takes greater effort to get ‘truly sharp’ in the first place.

Ed

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