Ashby on light weight bows...

[Kingwouldbe]

Hi Elknut1,

With all do respect your experiments buck the laws of physics, the main reason your light arrow out penetrates the heavy arrow is because of your EFOC ( extreme foreword of center ) which is a major factor.

Your light arrow has around 27% and is also a smaller diameter, and your heavy arrow has around 10% and a fatter diameter, impeding good penetration.

If you give me this info I can tell you accurately what your EFOC is for each arrow.

Arrow length =
Shaft+feathers+nock wt =
Separate insert weight =
Adapter weight =
Point weight =
Total arrow weight =
Balance length =   
   
There is only one negative in shooting a heavy arrow, and that is trajectory, it also makes a huge difference where the weight is in the arrow, move it forward, and WOW!!! it jumps through most anything.

Sir, you need to read this, then re-test, the good Doc. has 50+ years of testing behind him.

2007 Report, update 8
 http://www.tradgang.com/ashby/2007update8.pdf


KINGWOULDBE

[J from Denmark]

Ironcreek.
Yes I know the equation and yes there will be a point of return. but the fact is that the loss in speed is just not as big as the gain in arrowweight when going to heavier arrows inside realistic measures.
Here in dk we have to have use an arrow/bow combination that gives atleast 40 joule.
its common that people shooting light weight tradbows need to go to a heavier arrow to obtain the joule needed.
AND if we are talking momentum ( which we should be ) the gain in momentum when going to heavier arrows are quite huge ( not so with kinetic energy )

[J from Denmark]

Kingwouldbe, you nailed pretty much my main points in very clear speak, thank you

Still interested in hearing about your results though, elknut

[STICKDP]

I might be wrong but I dont think a 485 gr. arrow with 200 gr up front is 27% foc -- 27.25 " arrow

[SteveB]

 # There is no such thing as to many grains pr pound of drawweight when it comes to penetration.

.

True or not is irrelenant to me. I hunt deer mainly and occasionaly bear and elk. 8gns/lb has given me consistant passthru's.

I do know (for me) there is a "too many gr per lb for MY accurracy. Extra penetration potential
that sacrifices accuracy FOR ME is not a trade I am interested in exploring.

[J from Denmark]

Steve I agree completely on the accuracy part as I also have stated earlier

[Apex Predator]

Kingwouldbe nailed it!

[elknut1]

Thanks again for the input! Let's not get off track here, we are determining what arrow setup is best for the thread starters elk hunt & setup! Some are trying to shoot through brick walls & some of us just want to shoot through elk! (grin) In the tests I've shared up to now the 485grn aprox arrow wt. best suits him at 48#, it will go to bat for him delivering ultimate penetration & the best flat shooting arrow. The testing proves that bow weights in the 48#-55# are best suited with arrows in the 475grn to 515grn or so weight.

   A 615grn arrow or more is absolutely not needed nor realistic for 55# draws & under. Will it kill elk, yes! But so will a 370grn arrow at those draw wts. The best happy medium is in the middle. I've proven this many times myself on real live elk, not theory.

  And yes, I have tested various head wts & arrow wts. with the same diameter arrows. You just have to go back in this thread & read it all.

   As far as the latest tests done I used 2-701grn arrows. One with 270grn head wt. the other 165grn head wt. none-the-less both weighed 701grn, I wanted to see if there was a big difference? Both were on 2117 arrows cut to tune.I also tested a 510grn arrow with a 165grn total head wt. I only tested broadheads this time. One 2117 arrow had a 270grn ABowyer single bevel with steel adapter the other a Silver flame with the 165grn total head wt.

   After 5 shots each at 20yds into the dense hog target the Silver flame penetrated 3 3/8" on average, the ABowyer heavier head penetrated 4" nearly every shot. The heavier head wt. won out even though both arrows were identical wt. But there was a 105grn difference in head wt.
   To my surprise the 510grn MFX tipped with the Silver flame with 225 total head wt. penetrated identical at 4" with the 701grn ABowyer head. I felt the MFX should have went deeper but it didn't! (grin) It was a tie! But the MFX did best the 701grn tipped Silver Flame with the lighter head wt.

  Now for the serious testing! I shot all 3 of these setups into 1" thick Hardi Plank Cement board with the 2 different broadheads. Here's the results! The heavier head setup at 701grn with the ABowyer head stuck through the other side by 3/8" "impressive" this is tough stuff! The Silver Flame on the 701grn arrow at 165grn head wt. did not get through the 1" it made it aprox 3/4" 3 straight times, it would not bust through! Showing the heavier wt. head makes a difference even on the exact weight total arrow wt.

   I then took the 510grn MFX tipped with the 225 head wt Silver Flame & it too stuck out 3/8" on 3 straight shots getting great penetration but not anymore than the ABowyer 270grn head on the 701grn arrow. Both of these would blow through some serious bone if needed. --- I then shot the MFX at 15yds & 25yds & did the same with 701grn arrow. I picked point of aim using arrow tip at both distances so both were equal, at 25yds, the 701grn arrow had 29" of more drop than the 510grn MFX. Now examining the penetration results not only this time but in all the testing & given the flatter shooting what in your mind is the best arrow setup on ones elk hunt? No doubt the aprox 500grn arrow is the best choice!

  Couple of thoughts here. KE does play a big part in ones penetration value, no it's not an end all but neither is momentum, there must be a "balance" for the intended game you're hunting! Both setups were producing close to the same 42# of KE----As the one arrow gets heavier it gets slower but it does not lose much KE in the process until too heavy comes into play with the designated 48#-55# draw wt. But trajectory suffers greatly! Too fast, too slow, in the middle is best!

  The ABowyer head had a curled tip on first shot through cement board it did not get much worse in the following 4-5 shots but I was a bit taken back by it. The Silver flame head was unscathed, actually the pointed tip was still needle like, absolutely amazing. Too, it would still slice you if you weren't careful, that is the toughest head I've ever seen!

  As all can see I'm no expert here, but these test prove to me why my setups have never let me down on my hunts. 9-10grn per lb is major deadly & a great balance for an elk hunters setup, these wts will not sacrifice anything.

  ElkNut1

[IronCreekArcher]

Wow...I am surprised and a little bothered that the Abowyer tips curled.  Between my dad and I we spent $110 on Brown Bears and adapters.  What model Abowyer where you using?  Also, do you think the tips will bend on bone given its a "softer" material than Hardi-Plank?

[elknut1]

Yes, I was a bit surprised as well, but that's the way it happened! I would not let that bother you, the ABowyer head is a very good stout head & cement board is extremely tough & hard on things. Too, if you hit anything on an elk that's that solid you are already in a world of hurt. (grin)

  You would have to connect dead center on the leg bone or hit a scapulas partition before you experienced that kind of force, those shouldn't come into play as little good can come form it. There's plenty of kill zone on an elk to be flirting with leg bone or such shots. A rib itself is no match for any quality broadhead, so that's of little concern! Good Luck & don't sweat it!!

  ElkNut1

[IronCreekArcher]

Thanks elknut1...I was hoping that the whitetails around here were not that tough...  :D

My dad and I have been toying with the idea of an Alaska trip in the next year or two and I was hoping to get some field time with the Abowyers prior to that to boost the confidence.  I was hoping they would work well on Moose.  I am shooting a Black Widow PMA 49 lbs at my 28" draw with 525 grain Easton Axis N-Fused arrows tipped with the Abowyer Brown Bears.  Do you think that set-up will lend itself to adequate penetration in your opinion?

[30coupe]

Damn, I love this place! This has been a most interesting thread. For the most part there have been only civil disagreements here. Had this been started on most other sites, the flames would have been horrible to see (think Hindenburg).

Though elknut's scientific method sometimes makes me smile, he does make some valid points, and who can argue with his success on elk? I have often wondered at what point one starts to see diminishing returns on heavy arrows. It looks like the old-timers had it right with the 10 grains per pound of bow weight theory. Elknut's experiments also confirm that keeping the weight forward is critical to penetration.

At today's prices, shooting broadheads into cement board makes me cringe. Thanks for using your's elknut! I don't think I am brave enough to try that.

Thanks to you, elknut, and thanks to those of you who kept this thread both interesting and civil.        

[nightowl1]

Exactly what 30coupe says great place, great discussion, and great results!

[TNstickn]

Great thread. Thanks guys!!  

[elknut1]

Hey guys thanks! Nothing wrong with healthy debating, we can all learn from it, I know I sure appreciate others inputs, this helps me to even fine tune things a bit more without building that piano! (grin)
  30coupe--Yes I did bust a couple things up but it was worth it, tests can speak volumes, much more so than "it just stands to reason" (grin)

  I certainly agree with the extra wt up-front, there is much to be said for that! How much is more of a personal thing depending on total arrow wt & arrow materials used. For elk I like 165grn min but will be shooting 200grn up-front this year. I'm adding head wt but not increasing total arrow wt, my finish product this year will be in the 485-495 wt range at 55#.

  As another point of interest on the penetration difference between the 2-701grn arrows. Even though one out penetrated the other by only 5/8" don't take that too lightly. It may sound trivial but it's not. That difference in head wt penetration can be in the 3"-6" additional penetration factor. Meaning that suppose you hit a rib dead center & the broadhead busted it & penetrated 5" more on an elk with the 701grn arrow with the 170grn head. Take that same situation & have that extra 100grns up front even though the total arrow wt is the same & now that can mean 8"-11" total penetration after going through a rib. Just something to consider!


  Iron-creek--Your setup will prove deadly on Whitetails for sure! Personally I would probably opt for 490-500grn at most, but your is close enough that no real changes are needed. For your future Moose-Elk hunts I would make sure if you're using those arrow wts that you put at least 200grn of that wt up-front for best results. Those ABowyer heads will certainly do the job on those tough critters! If you can up your draw wt a bit for that moose hunt then even better! If not, stick with broadside shots no more than 30yds!

  ElkNut1

[overbo]

Elknut,
What where the shot distance of your tests?Also,have you done this type of test beyond 35 yrds?

[elknut1]

Overbo--

 The shot distances were mostly at 20 yards. But other ones varied from 15yds to 28yds. I stated all distances for the most part depending on the test done!

  I have not extended any comparison tests at the 30yd distance or longer except for our own setups! We have confidence with our 485grn--525grn arrows as long as we are in the right draw weight areas. If our draw wt exceeds this we then up arrow wt. We have taken a bull at 41yds with a 525grn arrow tipped with a Zephyr 2-blade with bleeders, the arrow passed completely through him on a broadside shot. The arrow was cedar with a 125grn glue-on, it was not a footed shaft. I like more head wt. but you can see what even 125grn will do.

  If you'd like I would be happy to test a particular arrow wt. for you at a further distance as a comparison, it's no problem!

  ElkNut1

[sdlane]

Iron-creek,
Alaska law requires at least 50 lbs draw weight to hunt moose, brown bear and goats, 40 for caribou and black bear.
Steve

[IronCreekArcher]

Your thread prompted me to conduct my own very "unscientific" test on penetration of different heads today.  Note I said heads not arrow weight.  I doubled over a vehicle license plate and proceeded to shoot it with my set-up.  I figured the aluminum plate would be harder to penetrate than bone on a whitetail seeing as though it is more malleable than "brittle" bone.  My set up is a Black Widow PMA 62" recurve pulling 49 lbs at 28".  My arrows are Easton Axis N-Fused 500's with a 100 grain brass inserts and 200 grain tip for a total arrow weight of 525 grains and 10.71 grains per pound.  My arrows were also bare shaft tuned and shooting bullet holes through paper.

The first head I tried was the Abowyer Brown Bear.  I stepped back to 20 yards and shot the arrow three times and averaged the results.  The arrow penetrated the plate an into my Block target consistently 4.5".  The next head I tried was an Eclipse double bevel 2-blade.  This head never fully penetrated the plate and only managed 1/2" of penetration.  The third head I tried was the Magnus II double bevel head.  This head also failed to penetrate the plate fully and averaged 3/4" of penetration.  The fourth and last head I tested was the Woodsman.  This head failed to penetrate the plate fully as well and averaged 1.5" of penetration.  The one thing with the Abowyers I noticed was the distinct rotating cut in the plate as it should.  

Take it for what it is guys and I hope this helps in some way.  This testing did tell me one thing for sure...Abowyers will be in my quiver this fall!

Best,
Dan

[JimB]

Go back and read the Ashby reports.The Abowyer Brown Bear has most of the penetrating features recommended by Ashby.Make any sense? I wonder if any of those tests are worth looking at?