Question about Tillering a R/D Bow AND Other Questions about Weight

[davidneils]

Thanks to Pat B for helping me the other day with a tillering question on a simple reflexed Ipe/Bamboo backed bow. Pat, your suggestion worked beautifully. I'm now sitting at 56 pounds at 25 inches before final sanding. My draw length is 28 inches so I'm sure I'll be close when all is said and done.

HOWEVER, pulling that bow back made me realize I really don't want to pull more than 56 pounds while hunting. Will I get the penetration I need on elk with this bow? I don't know. I need to feel confident out to 20 yards. That's why I'm going to experiment with a r/d design and see if I can squeak out a little better performance than just a slightly reflexed bow.

Tillering a R/D bow has always been a challenge for me. They typically come in under weight. I also lose the nice r/d profile at brace height, let alone at full draw. I'm drooling over the photos of the BOM bows that have beautiful r/d shape throughout the draw. How do you do that? How do you retain that r/d shape during the
tillering. Please post a few tips.

Also, this is the year I'd like to finally hunt with one of the bows I've made. Yes, I've taken small game with my bows but never big game. For those of you hunting elk, what weight are you pulling at your draw length? What is the maximum distance you'd feel confident shooting an elk at? I hunt with a 600 grain arrow tipped with a Wensel three blade head.

I welcome feedback about tillering and hunting weight.

Thanks,

David Neils
Fort Collins, Colorado

[Justin Snyder]

You could take it down to 50# if you are more comfortable and still use it for elk.  Shot placement is the most critical part of the equation.  If you hit the lungs, you only need to penetrate into the second lung. There is no need to go out the other side.  If you could shoot a 90# bow, but only gut shoot the elk because of accuracy issues. Or shoot a 45# bow accurately every time. I would recommend the 45# bow. So tiller the bow to a weight that you are comfortable with.  As for range.  I would say a 45 pound bow is good out to whatever distance you feel you can reliably shoot EVERY TIME. Anything inside of 40 yards the bow will do its job.  Justin

[Pat B]

I have never taken a large game animal with one of my own bows but I know they will do the job if I do mine. Like Justin said shot placement is more critical and I might add a broadhead that is ready for the task. Thr WW with keen edges is an excellant choice and being mounted to a 600gr arrow just adds to the momentum and penatration. With the set up you have and can comfortably and accurately shoot you should have no problem taking elk if you do your part.
   A 40# straight limbed bow shooting 130fps will take down any animal in North America if the shooter puts the proper arrow with a scarry sharp broadhead into the boiler room. Just look what primitive man used to survive over thousands of years. Most folks today would think of their equipment would be unethical to use, but obvoiusly it wasn't!   Pat

[StanM]

Hi David,

Here's my thoughts on hunting bows.  I've killed a couple of Roosevelt elk, a couple of bears and some deer with traditional bows, but I am by no means an expert.  So, take this as just one man's opinion.

Don't start with bow weight.  All bows, and I'd say especially selfbows, are different.  Start with the arrow that you intend to use while hunting elk.  Figure out the how heavy the arrow is, ready to hunt with.  Then shoot it through a chronograph.  If you get really carried away, like I tend to, you can even make a plywood "shield" by doubling a 3/4 inch sheet and cutting a hole in it the same size as your chronograph window.  With the shield in place, step back to 20 yards and shoot through the chrono again and see what speed your arrow carries at that range.  BTW, most chrono windows are approximately the same size as elk vitals so you could find your effective range this way as well.

When you've got your numbers you could compute your momentum and see where you are at.  As a guide you could use the numbers that Dave Sigurslid published in Traditional Bowhunter magazine for elk.  I believe he settled on 700 grain arrows going 150 fps or 750 grain arrows going 140 fps.

I can tell you from personal experience that a 625ish grain arrow, traveling approximately 170 fps, can break the rib of an elk on the entrace side and break a rib on the far side as well.  I've used a set up that produced those numbers four times.  Once with a complete passthrough and three times with the broadhead protruding from the farside, but with the shaft still in the animal.  This was with a Howard Hill longbow, not a selfbow.

As Justin mentioned above, an exit wound is not necessary, so I'm sure that you could kill elk less than what I've used in the past. 

One other thing, make sure that you tune your arrows really well, as I think that a true flying arrow is why some people get so much better penetration with lighter setups than others get with heavier setups.

Finally, with a well tillered #56 bow and appropriate arrows I sure wouldn't want to be the elk that you were shooting at

Hope this helps,

Stan

[Badger]

Stan, I like that method for testing a hunting bow, makes good sense. If a 55# self bow is shooting around 165 with 10 grains of arrow weight it will go to about 150 with a 650 grain arrow, that should be sufficient. Steve

[Pat B]

...also practice at very close range...3' or so on out to your max. Wouldn't it be a shame it you could punch the ace out of the middle of a playing card at 30 yards but can't get a good shot at 3' or 10 '. Does your arrow fly well at 3'? There is a very good chance that is where your shot can be.    Pat

[Coo-wah-chobee]

 What Pat said is important in Imo. I hunted rockies out in new mex on the Apache reservation some years ago. What REALLY surprised me was how close your shot can be ! Can be measured in feet not yards in alot of cases. This is where most of dont practice because we think its a given.......surprise, surprise ! Also as Pat said its your arrow more so than the bow or draw weight in most cases. .......bob

[Justin Snyder]

You ain't just kidding either Pat.  Of all the animals I have shot with a bow, one was outside of 10 yards.  I have not shot an elk yet. I have been close enough that had I released the arrow, It would have hit the elk before completely clearing the bow.  If you really want to maximize penetration, 2 blade broadheads or rock points will usually slip between the ribs. Then all the energy you would have wasted breaking the rib cage is used in penetration. Tapered shafts also reduce the friction on the shaft. Justin

[davidneils]

Thanks for all the replies! This is plenty to chew on. I've killed two elk, a bull and a cow. The cow was shot with a 55 pound recurve at 18 yards and the bull at 12 yards. In either case I'm sure a 56 pound selfbow would have done the job.

I appreciate the reminder about the arrow and scary sharp broadhead. I don't want to overbow my self and screw up my shoulder.

I'll post more tomorrow. Right now I'm on a carp cleanup mission at the local river. Here's a Bass I arrowed with one of my homemade bows.

http://www.telementor.org/images/davidn/bow_BAss.jpg


Thanks,

David

[davidneils]

Okay, I just reread the article by Jim Boswell in the April/May 2007 issue of Primitive Archer. Although it's titled, "A Reflex Deflex Glue Up" it has some good information about tillering. The article is based on a bamboo backed hickory bow. Boswell provides the following measurements: 1 1/2" wide 1" past the fadeout (I'm assuming on the way to the tips), narrowing down to 1" at the tips. THEN take the last three inches and narrow to 5/8 tips. He indicates this method will reduce handshock and improve performance.

If these are the suggested measurements for Bamboo/Hickory, what would you recommend for Bamboo/Ipe? I've thinned the Bamboo down to just under 1/8 inch thick.

The blank was glued up yesterday and will be ready to cut to profile in a few days. I used Bowgrip 100 and let the glue cure in the sun. The temperature in my space blanket hot box was around 110 degrees for four hours.

Thanks again for all the help.

[Pat B]

I'd say treat it like osage. Make it 1 1/4"=/- wide at the fades and either go out 6" or a straight taper to 3/8" tips with a slightly rounded belly. I prefer a 4" handle centered in the stave and 1 1/2" fades. The last 6" of the tips leave thick so you can reduce tip weight by reducing the width.  Depending on your draw length you could go 60"(or less) to 64" and easily achieve 55# to 60# or more.    Pat

[davidneils]

Okay Pat. Thanks for the measurements. When you wrote "go out 6" are you referring to a straight line out to 6" and then taper 3/8 tips?

I'll send a photo of the bow blank in a day or two. That way you'll see what I'm starting with.

Thanks,

David

[Pat B]

David, That was a bit confusing. It's late!   You can either go out 6" from the fades then taper to the tips or you can make a straight taper from the fades to the tips.   Pat

[davidneils]

Now that the r/d blank has cured I'll be taking photos of it tomorrow and posting a buildalong set of photos for feedback.