# Arrow Weight Differences?



## dchan (Jun 29, 2004)

It can weight but there are enough variables that we would need a lot more data to assist with this question. Arrow spine, distribution of weight (points, nocks, inserts, vanes/feathers, etc) bow configuration, Release type, rest type, etc.


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## guns_and_labs (Sep 3, 2012)

dchan said:


> It can weight but there are enough variables that we would need a lot more data to assist with this question. Arrow spine, distribution of weight (points, nocks, inserts, vanes/feathers, etc) bow configuration, Release type, rest type, etc.


Most everything else is similar or identical. Arrow spine .332 vs. .350, and that's about it. Points, nocks and vanes identical. Mechanical release. Whisker biscuit. Balance point the same to within 1/16" (about as tight as I can measure it myself). Really the only difference is the weight overall.

I should mention that my indicator of accuracy are three shot groups at 20 and 30 yards, 10 group sets, over 2 days, in my backyard range, alternating arrow types somewhat randomly.


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## dchan (Jun 29, 2004)

guns_and_labs said:


> Most everything else is similar or identical. Arrow spine .332 vs. .350, and that's about it. Points, nocks and vanes identical. Mechanical release. Whisker biscuit. Balance point the same to within 1/16" (about as tight as I can measure it myself). Really the only difference is the weight overall.
> 
> I should mention that my indicator of accuracy are three shot groups at 20 and 30 yards, 10 group sets, over 2 days, in my backyard range, alternating arrow types somewhat randomly.


It sounds like you had a pretty optimal tune with your old arrows so this now may make more sense.

Actually there are a lot of differences in those arrows, other than weight. GPI on the VAP arrows is 8.2, on the carbon express it is 9.4 GPI to account for the weight difference, the distribution of weight will change if you have the same grain points, nocks, and vanes. Stock nocks for Carbon express are 9 or 9.9 grains each depending on which ones you get. Stock for VAP arrows are Bohning F nocks and these are 6 grains. Looks like both brands are using the same Vanes. But adding 3-4 grains at the nock, can affect a good tune pretty drastically. Same with the actual dynamic spine which I'm sure has changed quite a bit for what seems to you as a simple overall weight change.

Balance point or FOC is only one piece of the equation regarding tune, nodes and flight so "within 1/16"" is not a very good way to tune for optimum flight/grouping.

Also .350 spine and .332 can be big. and lastly, Did you also reset your nock or whiskerbiscuit to account for the diameter change? It sounds real small but it can make a difference. Big difference if it is causing some sort of interference. Whisker biscuits are great at what they do (hold the arrow in place for hunting) with minimal impact to arrow flight but if not in perfect alignment when the arrow starts it's movement forward, they can have a much bigger impact to the arrow just because the whiskers will stay in contact with the arrow and fletches until the arrow has left the bow. No other way to get the vanes through the whiskers.

and oops. that previous post was supposed to say "it can BE weight..."


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## dchan (Jun 29, 2004)

Type of Mechanical release may also play a role in tune/spine determination, but by looking at the arrow selection, I'm pretty comfortable saying your arrows are not "matched" from one set to another and so they will not fly the same. If you re-tuned your bow to take advantage of the new arrows, you would probably get better results with the new arrows but the old arrows will suffer the same fate, and no longer be in tune with you and your bow. +/- 2gns can group fine if where the weight is picked up or lost is distributed properly.
0.5g advertised difference may not be overall weight but per inch. I don't recall how the mfg rates this. Also is the +/-0.5 grains advertised by the builder? is it for the shafts only? even 35.00 per doz points, in the same batch can vary by +/-1.0 gn and Nock and vanes as a combination are often .5-1 gns of variance. Generally they are matched within a batch of 12 but if you buy two different production runs they can vary quite a bit.

DC


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## guns_and_labs (Sep 3, 2012)

Thanks, that's all good input. I will try to address as much of it as I can, and see.

I did already weight sort the arrows, and reset the nocks... and I did find a significant increase in consistency/accuracy. 

I think I may switch out the whisker biscuit for a drop away, too, to eliminate that variable.

Edit/add: the release is a TRU Ball Stinger, that I've honed to mimic my rifle triggers. After 40 years of competitive rifle shooting I'm sure that a trigger is more consistent for me than learning a new release type. I'm not sure how that figures in, but I'd love to learn.


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## dchan (Jun 29, 2004)

guns_and_labs said:


> Thanks, that's all good input. I will try to address as much of it as I can, and see.
> 
> I did already weight sort the arrows, and reset the nocks... and I did find a significant increase in consistency/accuracy.
> 
> ...


Again weight/sort can be good or bad. Better to label (marker) and shoot them for groups. Then use them as groups instead of trying to figure out the weight component. Drop away would be more consistent. 
If you are shooting it like a rifle trigger (good thing) so your release will be consistent. How you are pulling against the wall (if using back tension with some rotation) or your arm (tricep/bicep) pulling back, may affect if the direction of release is perfectly straight or a little off the arrow line. Generally back tension is more consistent but harder to learn. Pulling straight back with your arm sometimes changes more with fatigue. Neither is "right or wrong" Both have advantages and disadvantages but having a coach look at this to see if it's consistent may be helpful. You may not be at that point either. with 52lbs and assuming 65+percent let off, That's probably not as big of an issue.


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## aread (Dec 25, 2009)

At short distances, the first things I would look at is nock straightness or fletching contact. I've seen some problems with Victory nock fit. A nock that is not perfectly aligned with the shaft can throw it off more than most realize. Imperfections at the back end will open your groups more than at the front end.

Another thing to check is spine alignment. There are expensive tools for this, but for most of us, simply making sure that the label is up (or down) on all shafts is close enough. The idea is to get the side with the stiffest spine in the same position on every arrow.

There are quite a few things that go into making arrows group better. The more you know, the better archer you will be.

Here are links to three threads started by Rod Jenkins that describes how one top pro prepares his arrows: 
http://tradtalk.com/forums/showthread.php?t=7154&highlight=madness
http://tradtalk.com/forums/showthread.php?t=7174&highlight=madness
http://tradtalk.com/forums/showthread.php?t=7442&highlight=madness

Rod is one of the top recurve archers in the game. He is also one of the most detail oriented archers around. As important as arrow preparation is to compound archers, it's even more important to recurve archers.

I hope you don't mind me inflicting this on you, but I find this subject very interesting.

Allen


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