Hopefully it will spread over the line into other states too.

Great reference and thanks for posting it here as well, David.

Whenever I get hosed trying to tout the benefits of heavier arrows and higher EFOC, most argue a heavy headed arrow will “nose-dive” at 20++ yards.

Gently nudging the wheelie’s I know, they admit they can’t afford fancy range finders and are lousy at estimating, so they want light, fast, flat shooting arrows.

The vendors touting all this technology and long shots, flat trajectory, etc, are the impetus for most of all this light, flat fast arrow stuff…

Getting people to change their thinking on anything, let alone “sportsman/hunters” is a huge job!

I am one of the authors of the “Arrows for Elk Hunting” article recently published as part of the “Elk Hunting University” on the Colorado DOW website. One of the issues we tried to address in the article, albeit briefly, was to estimate how much additional error (caused by misjudging distance) would be associated with increasing arrow weight be a certain amount. It turns out to be surprisingly small. So, the compound shooters’ fears may not be well founded in reality. We analyzed the error using a Windows program that I developed, backed up with a little testing at the range. If you are interested in trying the program, I would be pleased to send you a copy – it may help you convince the skeptics who are hooked on small, fast arrows. Send me a PM if you would like a copy to try.

Adrian,

I’m at best a ‘turn-key’ computer operator so that wouldn’t be for me…

Ashby and friends have done presentation at PBS sessions on stage showing how higher efoc projectiles actually have farther cast than low Foc ones.

If I’m not mistaken, the key is in the overall weight, not how much is front of center. A heavy rebar-weight arrow just to get front weight up, when starting with the heavier 8.9 gpi shafting, gets pretty heavy.

Guys shooting mid 60# draw and above likely don’t care. Those of us who have had to drop draw weight for varied reasons as we age, are more impacted. I’ve searched out lighter gpi carbon in order to keep overall weight under 600 gr or thereabouts. Doing so means lighter target shafting so I beef up the area behind the point with over-footing of alum shafting.

I have even had trad shooters out West tell me that heavy FOC shafts will nose dive. In theory, that makes sense, but not what Doc proved on stage in this demo done by varied folks around the country.

There are otherwise well intentioned and intelligent people that you just are not going to convince with FACTS!

Emotion is what most of us grow accustomed to using for personal decisions.

Doc Nock wrote: Adrian,

I’m at best a ‘turn-key’ computer operator so that wouldn’t be for me…

Doc, Adrian’s program is pretty much ‘turn key’. It’s easy to use and I’m finding it to be a great tool. Besides showing how small the effect on arrow trajectory is as arrow weight increases another neat thing is that it will let you see the drag effect of large fletch9ing, compared to smaller fletching. Worth having.

Ed

LOL, Ed…it’s that infamous part of your statement “pretty much turnkey” wherein lies the rub.

Only thing that I might need to learn on that whole thing is whether OVERALL arrow weight has little effect on trajectory, or that front weight has little effect???!!!

I’d presumed (?) that while EFOC has little effect on cast or arrow trajectory, I would have thought that total arrow weight might have an effect.

You and I discussed years ago how we bugged carbon arrow makers to INCREASE overall GPI, and now we search for LIGHTER GPI so we can amass front weight without shooting Lincoln Log total arrow weight.

Out of your “Man Bows” in that 80# range, I am certain it wouldn’t matter diddly squat. Out of my 47# high performance Sasquatch limbs, I do see an effect of trajectory if I let my overall weight climb just to get higher EFOC.

Perhaps the program could help me see that in real time measurably, but like you back in the motel days not wishin to put your laptop on line, I would be hard pressed to end up trying something new and hosing my only puter doing something I don’t know!

Doc:

I am not entirely sure what you are saying. But, let me say that arrow trajectory is caused by gravity working to pull the arrow toward the earth, and the effect of gravity does not depend on mass. You may recall one of the astronauts during a moon trip dropping two objects (one very “light” and the other very “heavy”) and they hit the ground at the same time. So, arrow weight does not directly affect trajectory. It INDIRECTLY affects trajectory by changing the arrow speed out of the bow. And a slower arrow goes a shorter distance during the time required for a given drop caused by gravity. Hence, a “loopier” trajectory.

Mass does have an effect, however. A heavier arrow will resist the effects of air drag, and will maintain its velocity longer than a lighter arrow, everything else being equal.

apfarmer wrote: Doc:

I am not entirely sure what you are saying. […arrow weight does not directly affect trajectory. It INDIRECTLY affects trajectory by changing the arrow speed out of the bow. And a slower arrow goes a shorter distance during the time required for a given drop caused by gravity. Hence, a loopier trajectory.

Mass does have an effect, however. A heavier arrow will resist the effects of air drag, and will maintain its velocity longer than a lighter arrow, everything else being equal.

Not sure if you’re addressing the REAL “Doc” (ED) or the one who plays one on the internet (me), but alas, you guys are starting to make my brain sweat and I’m frantically searching for my Drool Bib😯

As I understood the soda straw and coat hanger bow demonstration, which I participated in the R&D behind the scenes a wee bit, I thought the arrow weight was relatively the same, the draw the same but the mass was front of center on the EFOC one and that arrow went farther across the stage than “traditional” FOC weighted “arrows”.

I thought that the front mass and small feathers was what gave the EFOC shafting a better cast? Meaning less drag so more efficient use of energy imparted by any given draw weight bow.

Where I get confused is my interpretation that if the mass weight climbs, regardless of FOC, the arrow will have a more parabolic flight path?

Regardless, for ME…I strive for just under 600 gr. and 28% FOC out of my 47# bow. Finding the right spine to maximize the energy imparted without flailing about in flight wasting imparted energy is critical, but then EFOC seems to take over on a well-tuned arrow and give me a flatter trajectory.

BTW, with the incredible advances made by some bowyers, the actual “draw weight” of a bow seems to become more and more “moot”. I had a 50#, 49.5# and 47# bow… of 3 different bowyers and now my 47# bow by Bigfoot– required me to bump up in spine. There is THAT much difference in stored and released energy among the 4 different limb designs and materials!

I strive first for a well tuned arrow, and in seeking that, I search for 25% or higher FOC and have been quite pleased with arrow flight. My shooting however, can always IMPROVE! :roll::lol:

David Petersen wrote: Some here may be familiar with Colorado Parks and Wildlife (CPW) Department’s highly informative online “Elk University,” which covers essential aspects of elk hunting and after-hunt meat care for inexperienced elk hunters. The latest issue provides an excellent overview summary of some of the Ashby Study’s key points. This is a courageous act for a state agency and I can’t applaud them sufficiently. You can see it at http://wildlife.state.co.us/Hunting/ElkHuntingUniversity/Chapter4/Pages/ArrowsforElkHunting.aspx

A fellow traditionalist who has seen the “lesson” had this to say: “Wow … this is really awesome…the fact that they are using good practical data to properly educate bowhunters. Since I’ve switched over to Grizzly BH’s, properly sharpened, and strong heavy arrows I have not lost or wounded an animal. Made a terrible shot on a small yearling bull elk last year and he still went down in about 10 seconds. The bull wheeled on me at 25 yds., just as loosed an arrow….shot him in the left rear hind quarter quartering away from me. I shoot a 72 lb recurve and 690 gr arrows with a fairly high FOC. I drove that arrow all the way through the pelvis and severed the femoral arteries that come down through the tenderloin area.”

THAT is precisely the unforeseeable and largely unavoidable “less than perfect” real-life potential hunting tragedy that Doc Ed has worked all these decades to help us overcome. CO has more elk than any other state or province, and they want them DEAD, not wounded by hunters. Some incurable optimists of course will still resist and industry will raise nine kinds of hell, but this CO endorsement definitely will stir the pot amongst the toothpick arrow crowd.

And yet, other archers insist on using the lightest, flattest shooting rigs with mechanical heads that fail miserably when they encounter the leg bones, spine, or even the shoulder blade of the mere whitetail.

My mind boggles.

The Boggle is living proof that people will believe advertising before anything else… and the marketing pro’s know it!

So in the 5 years or so that I have been using EFOC arrows and single bevel blades I have found only one potential drawback. It seems to me that I am a bit less accurate with these heavier arrows that I am with lighter arrows.

After mulling it over a long time I got to thinking it may be due to the increase in time that the arrow is on the bow after the string is released.

I haven’t figured out how to accurately calculate it. But consider an arrow which leaves the bow at 150 fps compared to an arrow that leaves the bow at 170 fps. Not knowing the exact “acceleration profile” of a bow I just used averages.

Say you have a draw length of 28 inches. If the arrow starts at 0 fps and leaves the bow at 150 fps, then the average speed is 75 fps. For the 170 fps arrow the average is 85 fps. Converting draw length to feet gives about 2.3 ft. So the average time the arrow is on the bow for the 150 fps scenario is 2.3/75 or 0.03 seconds. For the 170 fps scenario is 2.3/85 or 0.027 seconds. The percentage difference is roughly 10%.

I have no idea if these numbers are meaningful, but it sure seems to me that the arrow is on the bow longer. For an archery hack like myself, it is a constant source of accuracy aggravation.

Any idea’s?

Steve,

Math is not my strong suit… but 3/100 of a second difference =10%???

I’ll take your word for it… Makes my head sweat… 😳

Whether it’s relevant or not, and no offense meant to your potentially expert knowledge and experience above my own, but last year, I got to talking to Troy Breeding on Doc’s recommendation.

Learned that my old standby “bare shaft planning method” of tuning (3 shots fletched vs 3 shots bare shaft comparison) was inadequate with EFOC or UEFOC arrows. Got Troy’s tuning guide off the Tuffhead site and used it.

OMG! I wasn’t “quite” as tuned as I thought. Also I’d tune 2 and then cut the rest. Troy enlightened me that in his past building competition arrows, he weighed, checked straightness and spine on every shaft in every dozen he bought and had to cull 2,3,or 4 from each dozen…suggested I tune each shaft..not batch cut.

I did. P/in the Butt, but it really helped. FWIW.

Steve:

Have you played with brace height? The brace height affects the amount of time an arrow is in contact with the string, and that amount of time can have a big effect on arrow flight.

apfarmer wrote: Steve:

Have you played with brace height? The brace height affects the amount of time an arrow is in contact with the string, and that amount of time can have a big effect on arrow flight.

I’ll second that notion of Adrians. Seemed whatever fast flight string I had it would stretch in hot weather. Until I got one of Rick Barbee’s strings. Way he build them: NO stretch. Period!

When mine stretched, my arrows were not behaving well and accuracy suffered… I was a good bit low on brace…made them appear to be out of spine.. moved brace back and bingo…excellentemente!

Getting everything tuned and keeping it tuned may seem to some as a never ending task.

Strings do stretch, releases do suffer at times and if all else fails the occasional brain #@%# always seem to creep in.:D

I’d hate to think what everything would be like if I tried to work thru a tune up right now.:shock:

I managed to get a little practice in before the season started, but lately there just doesn’t seem to be enough hours in the day for everything.

Thanks for all the suggestions. And I didn’t mean to hijack this thread. Probably should have started another. I have to whole heartedly agree that EFOC arrows are way better behaved than lighter ones. But there is a little something I just can’t put my finger on…

But hay that’s the fun of living, always having something to work on. Maybe it’s actually too much practice. I wasn’t able to shoot the bow for almost 2 weeks and then I went to our local shop for archery night and spanked the boys good.

Maybe that will be my new training regimen – Less practice, more beer 😀