Author Topic: How mainy grains per pound of draw weight is a "bench mark"  (Read 4078 times)

0 Members and 1 Guest are viewing this topic.

Offline dwardo

  • Member
  • Posts: 1,456
How mainy grains per pound of draw weight is a "bench mark"
« on: December 24, 2013, 07:43:55 am »
Hi all,

Thoughts on the above please? I was shooting in my osage bow last night and it felt a tiny bit shocky so i decided to try some of my other arrows. I found one arrow at about 480 seemed best but didnt scream out like the lighter arrows I had, weighing in at only 385. Spine wasnt a problem.

So how light is too light? Is it a comfort thing, or are there guidelines to follow?

Thanks.

Offline Marc St Louis

  • Administrator
  • Member
  • Posts: 7,870
  • Keep it flexible
    • Marc's Bows and Arrows
Re: How mainy grains per pound of draw weight is a "bench mark"
« Reply #1 on: December 24, 2013, 07:47:58 am »
Generally 10 GPP but if your bow is well made you shouldn't get any shock with 9 or 8 GPP
Home of heat-treating, Corbeil, On.  Canada

Marc@Ironwoodbowyer.com

Offline Del the cat

  • Member
  • Posts: 8,300
    • Derek Hutchison Native Wood Self Bows
Re: How mainy grains per pound of draw weight is a "bench mark"
« Reply #2 on: December 24, 2013, 07:48:30 am »
I think there are prob' guidelines for hunting arrows, but my guess is it's down to personal preference. Do you want a flat trajectory, smooth shooting or maximum hitting power?
I pretty much end up using about 400 grain arrows in everything until the weight gets up above about 60-70# but even then I'll still sometimes shoot the 400 grain ones.
Prob' 'cos I don't much like making arrows :laugh:

Just weighed on of my 'standard' arrows, 416gn and I've been using these to shoot in a 70# Yew stick ELB. Mind it does ring a tad >:D . I should prob go up from a 100gn point to a 150gn, or maybe an 11/32 shaft, but I'm keen to stress the bow hard to make sure it can take it.
Del
« Last Edit: December 24, 2013, 07:53:48 am by Del the cat »
Health warning, these posts may contain traces of nut.

Offline WillS

  • Member
  • Posts: 1,905
Re: How mainy grains per pound of draw weight is a "bench mark"
« Reply #3 on: December 24, 2013, 08:16:50 am »
I should prob go up from a 100gn point to a 150gn, or maybe an 11/32 shaft, but I'm keen to stress the bow hard to make sure it can take it.
Del

That's interesting.  I don't know the physics behind this, but in contrast Ascham writes in Toxophilus that a new bow should be shot with "heavy, dead" arrows to begin with, before going down in arrow mass for more constant use.  I wonder if essentially too heavy / too light do the same thing to begin with, making the bow work harder?

Offline PEARL DRUMS

  • Member
  • Posts: 14,079
  • }}}--CK-->
Re: How mainy grains per pound of draw weight is a "bench mark"
« Reply #4 on: December 24, 2013, 08:22:25 am »
Healthy bows deliver the lions share of their stored/created energy to the arrow and not the archer. You could just do what the wheelie guys do dwardo. Just keep adding chunks of "special" rubber to every nook and cranny until it goes away, then tell everybody your bow is whisper quiet!
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline dwardo

  • Member
  • Posts: 1,456
Re: How mainy grains per pound of draw weight is a "bench mark"
« Reply #5 on: December 24, 2013, 08:37:20 am »
It was more of a ring as Dell says. I know the wheelie guys shoot carbon drink straws from 80lb bows and as pearly says add dampeners.

I will have to go up in weight as it just feels better. At what point do we start to add/lose performance and safety for the bow?

I am guessing the answer will be complicated and probably from the flight guy's!

Offline dwardo

  • Member
  • Posts: 1,456
Re: How mainy grains per pound of draw weight is a "bench mark"
« Reply #6 on: December 24, 2013, 08:43:18 am »
Forgot to say though it was fun shooting these thin arrows from the osage which is probably 60lbs.
I had to use two haybales back to back  >:D

mikekeswick

  • Guest
Re: How mainy grains per pound of draw weight is a "bench mark"
« Reply #7 on: December 24, 2013, 08:44:53 am »
Might I suggest narrowing the outers a little from about 12 inches or so to the tips not because I think narrow outer limbs are the cure all for handshock but because I think you need a tad more bend there  >:D
I agree that even at 8 gpp a bow should still have no shock.
I think it could also be a limb timing issue. For this rest the bow just in the crook of your thumb and forefinger (no gripping) with your fingers open, close your eyes and then draw it back....feel for balance. Eyesight can trick you but with the eyes closed feel is all you've got! I often shoot in the dark at a lit candle as my last shooting in thing again with out 'gripping' the bow.
Anyway it's obviously only a little out if a heavier arrow settles it....but just shooting heavier arrows wouldn't sit right with me. Handshock is always a sign that something ain't quite tickity boo  IMO ;)

Offline artcher1

  • Member
  • Posts: 1,114
Re: How mainy grains per pound of draw weight is a "bench mark"
« Reply #8 on: December 24, 2013, 08:59:48 am »
Every one's bench mark differs according to their needs. For example, as I get older, and my draw weight goes down, I still have a minimum bench mark in speed and arrow weight I need to maintain for piece of mind. Once I go below that minimum, well, bullets type changes ;D

Offline Del the cat

  • Member
  • Posts: 8,300
    • Derek Hutchison Native Wood Self Bows
Re: How mainy grains per pound of draw weight is a "bench mark"
« Reply #9 on: December 24, 2013, 09:26:27 am »
I should prob go up from a 100gn point to a 150gn, or maybe an 11/32 shaft, but I'm keen to stress the bow hard to make sure it can take it.
Del

That's interesting.  I don't know the physics behind this, but in contrast Ascham writes in Toxophilus that a new bow should be shot with "heavy, dead" arrows to begin with, before going down in arrow mass for more constant use.  I wonder if essentially too heavy / too light do the same thing to begin with, making the bow work harder?
I'll happily agree with Ascham, but this bow has some longitudinal cracks and tons of knots... I want to provoke any problems into showing up early so that I can patch if necessary. It's a knotty stickbow made from a bit of Churchyard Yew I could get my finger and thumb around.
It's already had a fair bit of work on the upper limb.
http://bowyersdiary.blogspot.co.uk/2013/12/yew-stick-longbow-full-draw.html
If it can put up with the shock of a shooting lighter arrows it should be ok in normal use.
A heavy arrow is much gentler on the bow, giving slower smoother accelleration and leaving less energy in the limbs.
Del
Health warning, these posts may contain traces of nut.

Offline dwardo

  • Member
  • Posts: 1,456
Re: How mainy grains per pound of draw weight is a "bench mark"
« Reply #10 on: December 24, 2013, 09:57:17 am »
Might I suggest narrowing the outers a little from about 12 inches or so to the tips not because I think narrow outer limbs are the cure all for handshock but because I think you need a tad more bend there  >:D
I agree that even at 8 gpp a bow should still have no shock.
I think it could also be a limb timing issue. For this rest the bow just in the crook of your thumb and forefinger (no gripping) with your fingers open, close your eyes and then draw it back....feel for balance. Eyesight can trick you but with the eyes closed feel is all you've got! I often shoot in the dark at a lit candle as my last shooting in thing again with out 'gripping' the bow.
Anyway it's obviously only a little out if a heavier arrow settles it....but just shooting heavier arrows wouldn't sit right with me. Handshock is always a sign that something ain't quite tickity boo  IMO ;)

I am a hair over an inch wide at 12 inches from the tips at 3/8 nocks. I guess I can still lose some width there but as I was narrowing the outers last night i did start to see a tiny weight loss. But I have weight to lose so will go a little skinnier ;)

To be honest when it comes to actually shooting a bow I am pretty shoddy. I just dont practice. I make a bow shoot it until i am happy then another half finished bow starts winking at me from the corner of the shop and I am off again  O:)


Offline dwardo

  • Member
  • Posts: 1,456
Re: How mainy grains per pound of draw weight is a "bench mark"
« Reply #11 on: December 24, 2013, 10:00:28 am »
I should prob go up from a 100gn point to a 150gn, or maybe an 11/32 shaft, but I'm keen to stress the bow hard to make sure it can take it.
Del

That's interesting.  I don't know the physics behind this, but in contrast Ascham writes in Toxophilus that a new bow should be shot with "heavy, dead" arrows to begin with, before going down in arrow mass for more constant use.  I wonder if essentially too heavy / too light do the same thing to begin with, making the bow work harder?
I'll happily agree with Ascham, but this bow has some longitudinal cracks and tons of knots... I want to provoke any problems into showing up early so that I can patch if necessary. It's a knotty stickbow made from a bit of Churchyard Yew I could get my finger and thumb around.
It's already had a fair bit of work on the upper limb.
http://bowyersdiary.blogspot.co.uk/2013/12/yew-stick-longbow-full-draw.html
If it can put up with the shock of a shooting lighter arrows it should be ok in normal use.
A heavy arrow is much gentler on the bow, giving slower smoother accelleration and leaving less energy in the limbs.
Del

This osage bow has some drying checks that run to the tip one one limb and the last third on the other limb. I intend to silk back it anyway so i might be able to push it a little more compared to your knotty yew. That bow looks great by the way Dell.