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What spine arrow for a 40# recurve at 29” draw length

32K views 42 replies 26 participants last post by  Tracker1  
#1 ·
Hey everyone, I picked up a samick red stag bow to work on my form and play with. It’s only a 40# bow. I’ll be shooting it at 29” draw length so it will pull maybe 42# or so at my draw. I’d like to run carbon and aluminum arrows thru it. What spine carbon and size aluminum would everyone go with and how many grains out front would you start experimenting with?
 
#5 ·
based on my calculator which only goes up to 150g tip weight total. it's looking like 400, any more weight and you may need stiffer. how long are your arrows going to be? There are so many variables, I really reccomend you use 3 rivers spine calculator, it goes into the most detail with specific bows and arrow models too.
 
#10 ·
Based on that and if you are truly getting 42# at your draw, 400 minimum. But that is my opinion and experience, I have a 50lb stygian recurve that is around 43# at my draw and I got a weak spine indication until I cut my 400s down to 31" with only 125g tip weight. With more weight it will be even worse.
 
#13 ·
Identifying the design principles others found worked for their application and applying those principles to your system is a possible starting point. Or read everything published by a humble guy who utilized hundreds of hours studying and documenting controlled arrow tests on real animal bone/meat.





Your spine selection is a starting point that ought to reference your desired total arrow weight given your poundage and your particular bow variables, but will be finally determined after you bareshaft and knock tune. All arrow variable selections should lead to the goal of “Perfect Arrow Flight” and “Terminal Arrow Performance”. Of which are achieved after you work through the arrow build process.





This answers your


grain enquiry : Results — Ashby Bowhunting Foundation





Remember, bow shops are there to sell product. If you know the principles and know how to apply them, you can discern between bow shop junk and arrow penetration confidence and efficacy.





Happy Arrow Building.





May your blood trail be less than your shot distance,





Dustin
 
#41 ·
Identifying the design principles others found worked for their application and applying those principles to your system is a possible starting point. Or read everything published by a humble guy who utilized hundreds of hours studying and documenting controlled arrow tests on real animal bone/meat.





Your spine selection is a starting point that ought to reference your desired total arrow weight given your poundage and your particular bow variables, but will be finally determined after you bareshaft and knock tune. All arrow variable selections should lead to the goal of “Perfect Arrow Flight” and “Terminal Arrow Performance”. Of which are achieved after you work through the arrow build process.





This answers your


grain enquiry : Results — Ashby Bowhunting Foundation





Remember, bow shops are there to sell product. If you know the principles and know how to apply them, you can discern between bow shop junk and arrow penetration confidence and efficacy.





Happy Arrow Building.





May your blood trail be less than your shot distance,





Dustin
That's why I read so much on here, and am very thankful for what I learn. God bless y'all and may all your arrows fly true.
 
#16 ·
Not much clarity above. But this is a multiple variable problem and mathematical calculations are hard for those. So charts are not much help, it comes down to observation - with trial and error.

I don't do carbon shafts much. But aluminum and wooden shafts have similar characteristics. You asked about aluminum and carbon; I will not address carbon. I have used a 40# recurve and a fast longbow, drawn to 29+. I used 1916 aluminum shafts left full length ( which has changed now and then) and 125 grain points, give or take one step. Used some today and one old shaft maybe 30 years old, having been shot thousands of times. They are not as fragile as some folks claim. I would get a selection of point weights for tuning. 2014 and 2114 can be tuned to work, the latter with heavier points if you hunt.

For wooden shafts I used 50-54# cedar full length with 100 grain points, won the longbow national marked 3d champs with them. For hunting I used the same shaft two inches shorter with 125 grain points, having been broken at the front twice. That is my experience and observation, no charts nor calculations. - lbg
 
#25 · (Edited)
Not much clarity above. But this is a multiple variable problem and mathematical calculations are hard for those. So charts are not much help, it comes down to observation - with trial and error.

I don't do carbon shafts much. But aluminum and wooden shafts have similar characteristics. You asked about aluminum and carbon; I will not address carbon. I have used a 40# recurve and a fast longbow, drawn to 29+. I used 1916 aluminum shafts left full length ( which has changed now and then) and 125 grain points, give or take one step. Used some today and one old shaft maybe 30 years old, having been shot thousands of times. They are not as fragile as some folks claim. I would get a selection of point weights for tuning. 2014 and 2114 can be tuned to work, the latter with heavier points if you hunt.

For wooden shafts I used 50-54# cedar full length with 100 grain points, won the longbow national marked 3d champs with them. For hunting I used the same shaft two inches shorter with 125 grain points, having been broken at the front twice. That is my experience and observation, no charts nor calculations. - lbg
@longbowguy,
Way to disregard and mischaracterize the info I shared. The chart examples a well documented account of arrow weights that have proven bone penetration capability. I suppose if one disregards the context and omits the arrow building design principles which the chart supports, then you are absolutely right—way to let us know you have no clarity.

Furthermore You did a good job sharing your experience to example one of the arrow building principles I encouraged—bare shaft tuning.

Also, calculations is part of the process. As you said, “125 grains”. And no you dont need a chart, but some use charts to provide a reference in order to obtain a starting point that will lead to repeatable desired outcome. The chart answered the grain weight consideration question—that’s very clear.

You can specify something without making the input from others seem irrelevant.
First principles reasoning is a sound method for specificity—clarity as you put it.
 
#17 ·
I think Chad gave you a pretty decent starting point. If your dead set on going with 225 gr total, then you're going to be looking at .400's, maybe even stiffer. At a 29" draw you're probably going to need at least 30" arrows. You can go longer if you want to decrease your point on distance. I'd recommend you spend some time with the 3River Dynamic Spine Calculator. Should give you a good feel for what you'll need and help you see how different variables affect dynamic spine.
 
#18 ·
spine is so variable, with so many ways to go with details, & inputs, no one can set your arrow up for you and it's magically delicious.
You & I can both shoot same bow handing it back & forth and we will need different arrows - - even if we have the same draw lengths.
best you can do is get a test kit of .400s .500s and .600s and test kit of point weights - - 100s 125s 145s 175s & 200s.
And don't cut arrows.......keep them back for future endeavors with different bows. You will have more bows.
Screw in different point weights SHOOTING with the different spines to get the tune you need.
THEN order shafts......and points.
 
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#19 ·
I'll second Steve's suggestion as not to cut your shafts. In addition to various weights of points, you might want to also temporarily install your inserts so they can swapped out later. I've used a little Saran Wrap pushed in with the insert to hold it in place, and Bohning's Blue low temp hot melt has been very useful. With temporary inserts, it is best to stick to soft targets.
 
#20 ·
These questions and answers always strike as funny!!! Necessary, because we need things to discuss.

So let me start by saying .600, .500, .400 will work. Bows don't tune to one spine of arrow. Thank the arrow gods. Choices are all going to come down to arrow length and tip weight, plus tweaking things on the bow. Not to mention the use of the equipment WHEN TUNED.

Case in point. My draw is 29 inches. I have a longbow that is 50 at my draw - same draw as OP. For whitetails I shoot a .620 arrow with a 285 grain tip. For larger game, elk, moose, I use a .390 with a 360 grain tip. Let me assure you that both set ups shoot a perfect broadhead hole through paper at 12 feet and 12 yards. Both of these have numerous notches on their particular setup.

That's the arrow, the bow on the other hand has different strings and strike plates for each set up. I need a thin SBD string for the .390. which won't work for the .620.

The best advise, besides having a coach is to know this document backward and forward. www.fenderarchery.com/blogs /archery-basic/tuning-info

Bowmania
 
#22 ·
so to simplify it, Todd's situation - for his particular BOW and his particular DL - - both his .390 with HEAVIEs and his .620 with LIGHTer up front are effectively balancing out to the same finished arrow spine, since both arrows hit the same perfect holes at same yards. THIS is why no one will be able to PRECISELY answer you "built it to these specs" as you will have some experimenting to do. General beginning guidlines are a good thing though.
 
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#24 · (Edited)
40# and 29" draw is one of my bows. It shoots 500 spine carbons 125 gr point & 22 gr insert perfectly. I leave them 31" long, so they do stick out a tad more than I'd desire. Bump the insert up to 50 gr and I could chop off 1/2" arrow length. I think that ideally, I'd need about a 450 spine but I have a dozen 500's and they shoot very well bareshaft so I'll stay with it.
 
#26 ·
Get a test kit of shafts and points. Maybe some inserts as well. You can make almost any shaft work the above comments prove that especially if the bow is cut well past center. i proved that to myself. I see we went from “working on form” to a hunting setup. Try not to confuse form issues with heavy arrows dropping into targets.
 
#28 ·
I shoot two recurves. a 40 pound bow that I pull to 44 pounds at my draw length of 29.5 inches. Out of this bow I shoot a 31 inch, full length Fleetwood Carbon 400 spine arrow that weighs 7.45 grains per inch. This arrow is just under 416 grains, finished arrow weight, including a 125 grain tip. Divide 416 grains by 44 pounds and you get 9.45 grains per pound of hunting weight.

My 45 pound bow is 48 at my draw length. I shoot Gold Tip carbon trad arrows, full length at 32 inches. These arrows weigh 8.6 grains per inch, arrow weight of 460 grains, finished arrow weight including the 125 grain tip, Divide 460 by 48 and you get 9.58 grains per pound of hunting. I only shoot both bows out to 25 yards. I am getting a five inch group at 25 yards, which is inside the vital zone of a WT deer.

Another arrow that works good out of either of my bows is a 1916 Easton Legacy Aluminum arrow, 30 inches with a 125 grain tip. This arrow weighs 10 grains per inch, with a finished arrow weight of 485 grains, including the 125 grain tip.
Divide that by 44 pounds and you get 11 grains per pound of hunting weight. Divide it by 48 and you get 10.10 grains per pound of hunting weight.

All of the listed arrows work good out of both my bows, 40 pound drawn to 44 and a 45 pound drawn to 48 pounds. All of these arrows can be purchased online at 3 rivers archery. All of these arrows also fly good with two and three blade broadheads, from almost any manufacturer. This is just my mileage, your mileage may vary.
 
#30 ·
I shot my recurve today for the first time past 25 yards. I was shooting the 44 pound bow with the Fleetwood 400/s that have a finished arrow weight of 416 grains and I was putting them all inside a standard paper plate at 30 yards. I would never shoot at an animal that far, but they were flying really well. I am a big fan of the Fleetwood carbon arrow, full length at 31 inches, with five inch shield cut feathers.