64 inch 29 lb. hickory bow

[bassman211]

 I am trying to build a target bow for target shooting at my club. I had a 40 lb. reflex deflex hickory bow that I reduced to 29 lbs., so that I can shoot a volley of 50 arrows with out fatigue. It is all I can handle now with complete control. The bow shoots a 355gr. arrow which is the lightest arrow I have available through my chrony at 135 fps. Speed doesn't mean that much for the purpose at hand, but I wondering with a 290 gr. arrow how much arrow speed would I expect to pick up ? JUST CURIOUS.

[mmattockx]

Assuming the efficiency doesn't change and the lighter arrow gets the same amount of energy into it as the heavier arrow (possibly a large assumption), then you equate the kinetic energy of the two arrows and get

V₂ = (m₁/m₂)^1/2 x V₁

V₂ = (355/290)^1/2 x 135 = 149fps


Mark

[Selfbowman]

Mark not knowing the math that sounds about right to me. Bassman get some 5/16 shafts cut them to your length. Let’s say they weigh 300 gr. at 30”. That’s shaft only. If you cut them shorter you will lose about 9–10 gr. Per inch. Then barrel the shaft to lose another 60-70 gr. Put a 60-70 grain field point on and finish the arrow. You will easily get to 300 gr. I have ground the back of field points down to 60gr. Also. Some work but you don’t brake many indoors. 2” fletchings will help on speed also.

[bassman211]

Thanks for the info Mark, and Arvin. I was guessing 140 fps.  Present arrows bare shaft tuned nicely, but I would have no problems buying lighter arrows either. My arrow velocities always seem low, and some of it is, because my draw length is only 25 inches.

[sleek]

I am trying to build a target bow for target shooting at my club. I had a 40 lb. reflex deflex hickory bow that I reduced to 29 lbs., so that I can shoot a volley of 50 arrows with out fatigue. It is all I can handle now with complete control. The bow shoots a 355gr. arrow which is the lightest arrow I have available through my chrony at 135 fps. Speed doesn't mean that much for the purpose at hand, but I wondering with a 290 gr. arrow how much arrow speed would I expect to pick up ? JUST CURIOUS.

If you want a faster bow, are you against building a new bow designed to shoot faster?

[Badger]

 What is your exact draw length and is the bow 29# at your draw length?

[bassman211]

Sleek... yes I would be interested in a better designed bow for more speed even at 25lb of draw. Badger... my draw length is 25 inches at 29 lbs. I use a mark on the arrow ,and a weight scale to check, and repeat, and check ,and repeat. Sleek....with your design, and you building the bow what would you expect in arrow speed with the information above? curious.

[sleek]

Sleek... yes I would be interested in a better designed bow for more speed even at 25lb of draw. Badger... my draw length is 25 inches at 29 lbs. I use a mark on the arrow ,and a weight scale to check, and repeat, and check ,and repeat. Sleek....with your design, and you building the bow what would you expect in arrow speed with the information above? curious.

I might have some bows i could modify to those stats and find out actually.  Ill have to check. With a properly weighted arrow, I see no reason why 170 fps cant be reached. The arrows would start to resemble flight arrows at that light draw though just due to the need for light spine and light weight to meet even a 10 grains per pound.