In case you haven't noticed, Dr. Ashby's 2007 research, Part 4, just went up here. This part covers research on 54# bow penetration, extreme FoC arrows, single-bevel broadheads, broadhead mechanical advantage and more. Good stuff to make us think.   :cool:

Thanks for the heads up Dave.  I had not noticed myself.  Read the report last night and was amazed at how great the penetration increases were for optimally-designed arrows.  Extreme FOC and using the proper BH really improves penetration.  VERY useful information for all of us.  Well done Ed!

Thanks, John. Coming from someone as technically knowledgable as you, that's much appreciated. After a quarter century of hard work, there's finally getting to be enough data to pull everything together. I'm finally finding solid answers to some of what I wanted to know when I first started doing this stuff.

Ed
TGMM Family of The Bow

Doc, Thanks for all you have done, I think this is what Doctor Saxton and Mr. Young where trying to do when they where proving that an arrow and a bow are truly deadly weapons.

I had stumbled onto some of the things you have proven by accident and several that never even crossed my mind.

From one hard core Bowhunting-holic to another a tip of my camo hat to you Sir.


A little proof.56lb, 550gr single bevel 160gr Grizzly,shot 2-29-08

 


 

David, can that dark stuff I see on the ground possibly be blood? I didn't think single blade broadheads were supposed to leave blood trails?
   Is that hit just off the scapula's edge, or did it catch the scapular flat? That sort of looks like dirt on the BH too. Did the ground stop its penetration? Any more details? Tell me more.

Ed
TGMM Family of the Bow

Ed, since you're visiting the website now I have one question about using LocTite to anchor the BH+adaptor into the insert.  I too had wondered about the probability of RH fletch and RH bevel causing the BH to back out during the process of penetration.  My understanding is that LocTite offers various "bonding strengths".  Which one offers enough to prevent the BH from unscrewing itself yet can be heated sufficiently for removal without simultaneously removing the insert?  That seems like it might be a tricky operation.  My arrows to BOP are already 31.25", so adding a 3" BH (permanently) makes it hard for me to find rolling duffles long enough to swallow my hard arrow case.  Any recommendations for how to prevent the BH from backing out yet still enable (with some difficulty) it's removal without taking the insert with it?

John, it's difficult to apply (for me) but Teflon plummer's tape works fairly well too. I use the original, soft, thread locking LocTite (it's blue). The hard set versions are darned near perminent.

The other option: I use 48" and 52" zipper-open duffle bags. Bought an additional one at WalMart last year. Most of the time I use 4" PVC tubes for the arrows, and some of the test arrows have been on full-length shafts (to get the dynamic spine right). Those will fit inside the duffle bags I have. Option #3, it's east to get a bag made too!

Ed
TGMM Family of the Bow

Good stuff as usual Dr. Ed.  I'm still waiting for a good left-wing glue on single bevel head to hit the market.

With a 160 grain head and a hardwood footed and tapered 11/32 cedar shaft, I can get about 15% FOC.  Think I've figured out a way to increase it though.  Tap the shaft with about a 3-inch 3/16 hole and epoxy in a 3-inch section of steel rod, about 100 grains.  Not only does that increase the FOC substantially, since the internal footing will extend two inches or so behind the broadhead, it should also strengthen the shaft behind the broadhead.  One of my hunting partners and I have started experimenting.  Arrows fly real well.  Haven't had a chance to test them for toughness yet.  Thanks for all you have done.  Keep up the good work.

Jerry, I THINK there are possibilities there. I'm also encouraged from things I hear that a HEAVY glue-on single-bevel MAY show up in a few months. One geared at getting higher FOC on the wood shafts. Hang in there.

Ed
TGMM Family of the Bow

I would have thought if you have a rh thread unit, and you use right wing feather with the single bev grizz,  as the arrow goes in and turns, on impact, the shaft would tighten up the threads even more, before the broadhead actually starts turning.  This would be simple physics.    

Chuck, the bevel-induced roration is almost 4 times the rotational rate of the shaft in flight. Unless they are well secured, the more rapidly rotating right single-bevel BH loosens the threads on the more-slowly-rotating shaft.

Ed
TGMM Family of the Bow

Great read! Just hope some of your test results finds it's way into the compound world. I turn my head at some of the setups I see for the sake of speed!

I use string wax on the threads to keep things from unscrewing.

Blue LocTite works great for me.

Another concurrence, GREAT stuff!

To me it seems as if there are two primary topics in this whole research, one of which the good doctor set out to find (maximizing pentration) and one perhaps unexpected benefit (maximizing the wound channel) due to the "single bevel phenomenon" (of course there are many secondary topics/questions and hundreds of tertiary topics/questions) that have arisen from these studies.  The two main topics I see are:

1).  Penetration

2).  Wound Channel

I may have missed reading one study but it seems the #1 question has been answered thoroughly and decidedly.  The second item, "wound channel" being more extensive (than at least I would have first suspected) was possibly unpredicted?

I think where the most likelihood of pulling in rank-and-file bowhunters to utilizing the "single bevel phenomenon" will take demonstration that the wound channel isn't just a slit and that the rotation of a SB thru SOFT flesh can result in more extensive SOFT tissue damage and thus better blood trails than multi-blade heads can provide.

I think bone hits for most NA bowhunters is a lower concern compared to making as large of a wound channel as possible which means soft-tissue damage due to the smaller, finer boned average- sized animal that is hunted over here.

(that said, I haven't created my first SB wound channel yet but looking forward to doing so to verify results of these studies!)

I've enjoyed the entire study. I think this may be the most well received information to date.  Certainly applicable (bow weight/arrow performance) to a large portion of the tradbow community.

To me, the most important part of the study is the establishing of optimum penetration performance.  If you know what is the absolute best combination, then you know how and where you are giving up penetration performance for other characteristics that may be important to you.

As for blood trails, I don't believe it matters.  Hit something that bleeds alot, leave an exit hole, and you will have no problem following the trail. The poor bloodtrails I've followed have been from poor hits, or hits that did not exit. The quality of the bloodtrail has everything to do with the sharpness of the broadhead and where you hit. If you can follow the blood to your deer, it's a good bloodtrail.

There is no such thing as overkill when bowhunting.

I too have enjoyed and learned alot from Dr Ashbys` reports.  

The young hunters in my home have, and will continue to benifit from the information put forth by Dr. Ashby. As for me, my arrows are heavier than they have ever been, my front of center is way up, and while I don`t use single bevel heads, my young sons certainly will be.

Thank you Dr. Ed Ashby... I hope someone DOES come forth and asks your permission to name a broadhead after you. You have done bowhunters
the world over a great service.    

P.S. Are those huge buffalo any good to eat once they are reduced to fit on a dinner plate?

I know that my setup has changed based on the many reports from Dr. Ashby-example...no more aluminum inserts. It's fun to hang out here and have fun but (more importantly) this kind of great information has made me a more efficient and sucessful hunter.

Thank you all for the kind words. Ya'll are the folks that make it all worthwhile.

Donald, buff are great eating! The big ones can be a bit tough at times, but that's never been a problem. Just cook them slow and long and they fall apart. Love my Dutch Oven!

Ed

quote:

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Originally posted by Dr. Ed Ashby:
David, can that dark stuff I see on the ground possibly be blood? I didn't think single blade broadheads were supposed to leave blood
trails?

     and single blade broadheads can leave good to great blood trails, But I know you already know that.    

They just don't leave a gaping hole like some of the 3&4 blades do.

I will take penetration over any other factor, I want an exit and two holes are always  better than one.

The arrow did just miss the scapula but it blew up ribs on both sides before hitting the ground stopping the shaft.

One of the things I do now is that TANTO tip you talk about, WOW!! is that thing strong.

I use to round it off and had far results, but the TANTO tip seems to split or blow up the bones.

As you can see from the hit it was vary strong down hill right through the thickest part of the shield, I still had another 2-3 inches to the right before I would of been out of the chest cavity.

You already know the  heart sits right between the two front legs, I wanted a quartering in shot, but settled for broadside    with a few more improvements to my set up, crushing the scapula wont worry me.  



I just wanted to share with every one how much you have helped me and improved my set up, Thanks again Doc.