Selfbow FPS?

[Carson (CMB)]

Back to your original question. Yes, you do impart more energy into the target from a heavier bow shooting 10 grn/# over a lighter bow shooting 10 grn/# , even though speed is constant.   E = mc2   duh! 

My favorite example of why mass over speed matters for hunting is Dr. Ashby's account of the present day Papa New Guinea hunting large deer with 80# bamboo bows and 4,000 grn arrows!!!  Do a search for Ashby papa New Guinea arrows to find the downloadable pdf. 

Ashby judged the arrows to be flying no more than 100 fps.  These native hunters take deer at 30 yards with 4,000 grn arrows!

[PatM]

You have to wonder about hunters in NA going on about deer jumping the string and yet in New Guinea the deer wait for an arrow to cover 30 yards at 100fps.
  Not sure if it worth differentiating between a Deer and an Elk. They are all Deer.

[half eye]

What ? jumping the string is a result of untoward noise, and please correct me if I'm wrong but a 4,000 grain arrow from an 80# pound cant be very noisy as far as excess energy generated by shooting light weight arrows from heavy bows is. One is straining it's guts out, and the other is down to near dry-fire.....quiet is still better.
rich

[Carson (CMB)]

You have to wonder about hunters in NA going on about deer jumping the string and yet in New Guinea the deer wait for an arrow to cover 30 yards at 100fps.
  Not sure if it worth differentiating between a Deer and an Elk. They are all Deer.

The only difference is about 400 lbs and 1/4" hide thickness.   

The New Guinea have no problem because that 4,000 grn arrow quiets the bow down to nearly noiseless.  They stalk to within 30 yds in the wide open grasses and shoot the dear while it is looking right at them.  It seems their silent set-up does not alert the deer.  Just lobs a spear into their vitals. 

Most NA bowhunters shoot really loud set-ups. 

[Carson (CMB)]

half-eye beat me to it.   

[PatM]

Is it really quiet to a deer though or simply a less threatening sound?
 The "Deer" of New Guinea are  more closely related to the NA Wapiti in at least one case. All are introduced species. My point is that the Deer versus Elk size difference is very blurry depending on what type of Deer we are talking about and the age of the animal.
 A Sika Deer or Red Deer are cousins to our Elk.

[Carson (CMB)]

Is it really quiet to a deer though or simply a less threatening sound?
 The "Deer" of New Guinea are  more closely related to the NA Wapiti in at least one case. All are introduced species. My point is that the Deer versus Elk size difference is very blurry depending on what type of Deer we are talking about and the age of the animal.
 A Sika Deer or Red Deer are cousins to our Elk.

Pat, PAhunter is preparing for an Elk hunt and appears to be shopping around for peace of mind that his gear will get the job done  .  Others were making reference to pass-troughs on whitetail deer. Not sure stories of passthroughs on whitetails are going to give PAhunter, who has experience with elk,  the confidence he needs. That is all I was aiming at.   

[Badger]

  Several years ago I made a bow for a guy that he took on one of those canned hunts for a cow buffalo. She was almost 700#. The bow was about 54# and just slightly reflexed, 500 grain arrow. I don't know if he got double lung or not but he said it coughed up a lot of blood as soon as he hit it and it ran about 100 yards.

[PatM]

Pat, PAhunter is preparing for an Elk hunt and appears to be shopping around for peace of mind that his gear will get the job done  .  Others were making reference to pass-troughs on whitetail deer. Not sure stories of passthroughs on whitetails are going to give PAhunter, who has experience with elk,  the confidence he needs. That is all I was aiming at.   

  You can probably still find a bunch of guys that will argue that a bow that will allow pass through on a whitetail is good enough for Elk.

[Carson (CMB)]

Pat, PAhunter is preparing for an Elk hunt and appears to be shopping around for peace of mind that his gear will get the job done  .  Others were making reference to pass-troughs on whitetail deer. Not sure stories of passthroughs on whitetails are going to give PAhunter, who has experience with elk,  the confidence he needs. That is all I was aiming at.   

  You can probably still find a bunch of guys that will argue that a bow that will allow pass through on a whitetail is good enough for Elk.

I am sure you are right about that.  A 40 lb bow with a good weight arrow will work for elk, if you do your part.  I wasnt trying to argue it wont, just not sure PAhunter would find the conviction he needs from the deer pass-through testimonials, and wasnt sure if people understood he is gearing up for elk hunt. 

[Carson (CMB)]

Why are you considering KE? There's not enough velocity to make it relevant.

I hear some archers discussing it yesterday and it made me wonder about selfbows.  I'm looking for a good way to compare the potential penetration of bows given different DW and FPS.  The goal would be to help answer questions such as:
How much more effective is a 60# bow over a 50# bow?
What kind of FPS should I be trying to get when hunting elk?
How heavey of an arrow should I be using?

Personal experience and opinions are great but I was looking for a more concrete measurement of effectivness.  I was not aware the KE was not a relevant measure when it comes to bows.  I'm just trying to enter the woods with confidence that my equipment will be effective.

I appreciate your advice!

I am not sure why KE would not be relevant, as Adb states..but hey I am no physician 

To answer your questions I would say the bow that you can shoot a good hunting weight arrow (10-13g/#) accurately is the most effective elk hunting weapon.   
Forget about arrow speed. 

And be sure to use a good cut on contact two blade broadhead.  Or a sharp stone 

[loefflerchuck]

How would you modify it for short bows with a short draw? Would the arrows be 17.8 grains less for every inch under 28" for 50# and so on? Lets be fair here. Not everyone shoots a 28' draw. Anybody have a better formula?

[mikekeswick]

what did we do before bows (and atl-atl's )?

Spears, sticks, and if you go back far enough flint rocks to scavenge off of others kills with.  But it's not legal to hunt with spears in my state for some reason.   

Before projectile weapons we used a thing which is now known as persistance hunting. Run after your prey until it overheats and cannot carry on.

[Del the cat]

what did we do before bows (and atl-atl's )?

Spears, sticks, and if you go back far enough flint rocks to scavenge off of others kills with.  But it's not legal to hunt with spears in my state for some reason.   

Before projectile weapons we used a thing which is now known as persistance hunting. Run after your prey until it overheats and cannot carry on.

I thought that was 'courting' 
Del

[Gsulfridge]

what did we do before bows (and atl-atl's )?

Spears, sticks, and if you go back far enough flint rocks to scavenge off of others kills with.  But it's not legal to hunt with spears in my state for some reason.   

Before projectile weapons we used a thing which is now known as persistance hunting. Run after your prey until it overheats and cannot carry on.

I thought that was 'courting' 
Del

Ha ha ha!  Good one!!