A question for heavy poundage shooters (70# and up)

[Matabele]

By diminishing returns I was meaning efficiency, and I agree with Rick and O.L. that the benefit of increasing draw weight is to increase your gr/lb while keeping roughly the same speed compared to lower poundage bows at the same gr/lb.

But i guess the flip side is you could drop the gr/lb say from 11 to 10, gain some speed, flatten the trajectory and still have a relatively heavy arrow.

Interesting stuff.

[longbowman]

The "dimenishing return" thing was created by people who can't or choose not to shoot heavier equipment.  I agree with Dr. Ashby in the way he built up to his bows.  You don't need to be built like Denny Sturgis to shoot heavy equipment and for me I like having the extra umph if the shot strays from where I'm looking.  Now there are physical limits to a degree for everbody and it doesn't take much change in weight when your at or close to your limit.  My play bow is 70# and I can shoot it all day.  My hunting bows are 80# and I shoot 3D with them with no problems if I jump to 85# I get ate for lunch.

[Grant Young]

Good points Rick. To tell the truth, I never really think about this stuff until it comes up in conversation or on a post. For better or worse, my background is of the "shoot the most bow you can shoot well or feel you can handle) philosophy, so I do. I also can identify with the arrow tuning component of your first post. Unfortunately if I get much beyond 75 lbs. I don't really shoot well enough to determine if its me or the arrow that causes the flight issues. I have to figue its me, lol. I also agree that increasing bow weight necessitates shooting progressively heavier bows until the shooter's "comfort zone" is enlarged. I probably subconsciously factored myself into the equation.Good commonsense post.       Grant

[Dr. Ed Ashby]

Mark, most of my hunting today is done with one of my three 82#@27" longbows, but I still do draw exercises with my 85#, 90# and 100# bows, and still shoot the 85# and 90# ones frequently.

Nowadays, it's about all I can do to manage the 100# big-five for a few shots. Most of the heavier bows are still there, and I don't doubt that I could still work right back up to them in a few short months. However, with the advances in terminal performance shown with the EFOC arrows, what I'm now getting from my 82# longbow exceeds the terminal performance I once achieved with the 100#+ bows and normal/high FOC arrows - at least on game to buffalo-size.

From time to time the thought crosses my mind; and EFOC arrow setup from one of the truly heavy longbows. Ah, if only I were a bit younger, and Africa was still what it was back when I WAS younger ...      

Ed
TGMM Family of the Bow
 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=93;t=000366

[Str8Shooter]

I should have clarified earlier that one of the biggest reasons for shooting a heavier bow is to cast a heavier arrow at a similar speed to an equivilant lighter setup. But, my point was that increasing draw weight in a different design may not yield any difference in performance.

For example, if you currently shoot a relatively high performance recurve switching to a heavier mild d/r longbow might not give you any tangible increase performance. It might even give you less.

I remember reading something about from Paul Brunner once. He was talking about an upcoming hunt and mentioned his setup. He said after chrono testing his 2 bows he was going to hunt with one that was lighter (by 8-10 lbs, I think) because the heavier one didn't yield any more energy.

All I'm saying is that if you're going to go up in weight make sure that you get a positive change from it. No sense in pulling more weight and getting less in return.

[O.L. Adcock]

Str8, "For example, if you currently shoot a relatively high performance recurve switching to a heavier mild d/r longbow might not give you any tangible increase performance. It might even give you less."

Very true, more is not automaticly MORE, and it seems the differences in bows beyond 65# is greater then it is below....O.L.

[Dr. Ed Ashby]

Chris, you and O.L. are spot on. There are certain reasons why I prefer a straight-end longbow for hunting, and those have nothing to do with bow efficiency. I do have to use more bow force with them to get the terminal arrow performance I want.

That said, I can tell you from my side by side testing that the average velocity for a ten shot string with one of O.L.'s ACS-CX bows, pulling 64# at my 27" draw, EXACTLY equaled the velocity of the 82#@27" straight-end longbow I've used as the 'baseline' for the buffalo testing - using the exact same arrows. And I tested that across a range of arrow weights from 780 grains to just shy of 1000 grains. When tested on buffalo, the arrows from the ACS-CX performed exactly the same as they did from the 82# straight-end longbow.

As for tuning, I was able to get the ACS-CX to tune to the exact same arrow setups I use for the 82# longbow by by building the arrow plate out. That was done before chronographing the velocities.

I figure that it won't be too many more years before age catches up with me, and I'll have to drop down in bow weight. It sure is nice to know that there are bows out there that will allow me to do that without giving up the performance I've gotten with my beloved straight-end longbows.

When it comes to choosing between the bow design I love to hunt with and the performance I want from my arrows; terminal arrow performance will win. The animal will never know what bow the arrow came from, but I don't doubt that I'll miss using my favorite style of hunting bow; sort of like a fly fisherman forced to use a spin-caster for trout.

Ed
TGMM Family of the Bow
 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=93;t=000366

[Kingwouldbe]

Doc, you had me until you went from Fly rod to spin-caster (that's to big of a jump for me)LOL

How about Bamboo Fly Rod to Graphite Fly Rod, you're still shooting a Longbow.

[Dr. Ed Ashby]

Okay David, you got me. From a hexagonal split bamboo fly rod to a carbon-fiber fly rod IS a much better comparison.      

Ed
TGMM Family of the Bow
 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=93;t=000366

[Cory Mattson]

every day bows are 65# & 67# throwing 700 to 800 gr arrows - nice performance - shotts flat I guess - through hay bails into the second set ------- my heavy bow is 85# ----- don't know anything about trajectory - they all seem about the same - but the heavy bow - at roughly 20 more #'s blows through 2 sets of hay bails and bounces off my shed with a loud thump at 30 yards!!!!!!!!! - well worth the extra weight - and the extra weight throws arrows 1050 grains.
I do like to shoot 10 or 20 arrows with a 70# bow before getting into the 85# - easy!
<>< <--------------------<<<<<<<<

[O.L. Adcock]

Doc, I'll make you some split bamboo buffalo arrows while you are here. You want weight, spine, and small diameter that's the ticket! Ultra hi FOC while we're at it.   ....O.L.

[Dr. Ed Ashby]

Well, O.L., my intent IS to start testing Ultra-EFOC arrows on the next go around!      

Ed
TGMM Family of the Bow
 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=93;t=000366

[Kingwouldbe]

OK, for us slow guys, what would be the optimum performance for a given bow  & arrow weight.

Lets say:
50lbs.
60lbs.
70lbs.

Where do I get the best performance, lets use  a curve between flat trajectory and penetration.

I all ready know light is flatter and higher speed, but less penetration, I also know heavy weight is slower (drops quicker) and penetrates deeper.

Where is the balance, or where is the optimum performance (like what you said Doc.) about shooting a 64lb bow with the same performance as an 82lb'er. that's 18 more pounds of force for no return.

I hope you or O.L. can give some light on this.

[Dr. Ed Ashby]

David, I think O.L. will have to carry the bulk of that answer, Re: the bows. All I can contribute is that the heavy bone threshold is very real and very persistent, at something very near 650 grains of arrow mass; and that all testing so far indicates that arrow FOC has either very, very little or no effect whatsoever on it.

Once through bone arrow FOC becomes a huge penetration factor. I'll have to qualify the following remarks though. They apply only when the best performing broadheads, having single-bevels and high mechanical advantage are used. In essence; for arrows that take every available chance to maximize the use of whatever force they carry, in all regards excepting their amount of FOC.

I'm just now scraping the surface of Ultra-EFOC, but everything so far SUGGEST that there's no upper limit to FOC's soft-tissue(s) penetration benefits. The higher you push the arrow's FOC, the greater boost in penetration it shows - once the bone is breached. In the long run, this MIGHT just mean that, at trad bow velocities, any arrow with a mass above the heavy bone threshold COULD represent thorax-traversing penetration, even on game as large as buffalo, IF the FOC is sufficiently high. I should (I hope) know much more about this whenever I can get through another round of testing.

Ed
TGMM Family of the Bow
 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=93;t=000366

[Soilarch]

My goal isn't to hijack so if people want to respond by PM that's fine. These question do come alongside the topics of heavy bows.

Has anyone done comparisons on the "efficiency" of popular bow designs? Kind of what Kingwouldbe asked. I know LeTub posted a thread not too long ago comparing 4 or 5 bows.


EFOC...I've been looking into this while trying to get a rough guess what I'll buy for my first setup.  EFOC just makes sense to my mind so I'd like to go as high as possible before they start dropping like rocks. You can only "weaken" the spine by building the pad out.  Are there tricks to strengthen it for using heavier heads.  I know both of these can be considered "bandaid" fixes but it should would make experimenting with different FOC a LOT cheaper.  (Of course, it would probably be smarter to wait until Dr. Ashby tells us the findings of his experimenting...but I know myself better than that.)

[Kingwouldbe]

Doc. I always appreciate your expertise, I'm one of those "show me" guys before I give it any consideration.

You proved things I was doing and didn't know why, I just stumbled on to most of it.

Thanks.

Please for give me Matabele  for hi jacking your thread ( but we are learning some things )

[marlon]

Been shooting 100# plus bows for the last 11 years. Heard that 65 after dimish return like doc said you need more weight to hunt huge game. Marlon

[Matabele]

King, no need to aplogise at all. As you say we are all learning stuff here from throwing ideas around.

There's some great info in this thread, thanks for the replies!

[Pat B.]

I'm going to get blasted here but that's ok...

Just an observation for those who push the limit.

Eventually you will (might) suffer for pushing the limits of your strength.. But I'm not about to say not to enjoy your pursuits, beware that you may have problems in the future.

I was never a "big" guy but did weigh in at over 200 when in my 20's and 30's and fairly strong for my size.. I shot big bows and felt good while doing it.. Now, 30 years later, I'm having all kinds of joint and connective tissue problems and consider myself dam lucky to be able to shoot in the mid 40's. And I can only do that on a limited basis.. I realize that some of my issues may be genetic, perhaps not..

Enough, enjoy !

[longbowman]

I believe that you can shoot the weight you want for nearly as long as you want if you continually work at it.  I'm sure my body will hit "diminishing returns" quicker than the bow will.  I'm 54, 5' 8" 150# and have been shooting in the 80 # range for mu entire career.  My son is 30 , 135# soaking weight and loves his HH 80# @ 27" bow.  You just need to shoot the stuff to be able to do it.  Currently, I don't have as many aches and pains as most guys who don't hunt.