# Arrow weight tolerances (new grain scale)



## granite14 (Nov 10, 2014)

Just bought a grain scale. The arrows I might use for Darrington, I had 2 groups at 10 grains apart, within the groups (VAP V3 350 spine w/ feathers, 100gr points) they were very close.

My recurve arrows (VAP V6 500 spine /w vanes, 120gr points), had 3 groups of weights with 11 grains from lowest to highest. Even within the groups, they still varied by a few grains.

I wonder if this has lost me any points? I've never looked at the effect of 10grains height difference at any distances.
I'm shooting these barebow recurve and barebow compound.

Does everybody weigh and group their arrows, or try to make them identical?


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## Viper1 (Aug 21, 2003)

granite - 

I've never had a dozen complete arrows with a variance of more than a grain or two. 
10 grains is a huge difference and will be noticeable as close as 20 yards.









This is the difference 30 grains makes at 40 yards.

Viper1 out.


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## ccwilder3 (Sep 13, 2003)

granite14 said:


> Just bought a grain scale. The arrows I might use for Darrington, I had 2 groups at 10 grains apart, within the groups (VAP V3 350 spine w/ feathers, 100gr points) they were very close.
> 
> My recurve arrows (VAP V6 500 spine /w vanes, 120gr points), had 3 groups of weights with 11 grains from lowest to highest. Even within the groups, they still varied by a few grains.
> 
> ...


The weight differences with the lower grade VAP's is terrible. I ran into the very same thing with the .003's. 

That much difference will show big time at longer distances.


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## Nick728 (Oct 19, 2014)

I just bought Carbon Ones. They came in at less than 1 gr difference.


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## limbwalker (Sep 26, 2003)

Of the three measurable tolerances for arrows (spine, straightness, weight), weight has the least affect on accuracy - especially for the finger shooter. 

Years ago, I had a set of wood arrows for my longbow that happened to be the same spine as my Olympic recurve arrows. They were hand selected for spine and were nearly as close in tolerance for deflection as my A/C/E's. I hand straightened them as close as I could. Across the dozen, the weight varied quite a bit. 25 grains if I recall. 

Out of curiosity, I shot them through my Olympic bow at 70 meters and believe it or not, was able to hold red or better with a dozen wood arrows that varied by 25 grains. I did this over and over until I was satisfied that weight and straightness (the two most often advertised tolerances) are of little consequence so long as the spines are close.


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## droy (Dec 21, 2012)

all my v3's are with a grain or 2


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## dchan (Jun 29, 2004)

John, did you plot arrow by arrow? Did you find that heavier arrows impacted lower than lighter? Was there a pattern?


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## dchan (Jun 29, 2004)

The big problem with trying to test arrow weight is by changing a point for instance, we affect dynamic spine. If we add tail weight we also affect spine. Changing shaft size or length will affect spine. So how do we know if its quality of flight because of a spine change or the weight that changes the elevation.

Because wood can have different densities and were individually tested for spine, and I presume points, nocks and feathers were all within a grain, that John's test would be about the closest we could get to a good metric.


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## Huntinsker (Feb 9, 2012)

I've never had arrows more than 2 gr different from top to bottom. Just built a set of 810 Carbon Ones for my wife and they are within 1/2 of a grain from the heaviest to the lightest, I was impressed with that. You'd for sure see a difference from 10 grains. If I saw that much of a difference, I'd be worried that a few of the shafts were mislabeled and are actually a spine weight heavier or something like that.


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## Viper1 (Aug 21, 2003)

Guys - 

Just for the record: The arrows in the picture weighted approx 350 grains and 320 grains.
Through a chronograph, from a 42# bow, drawn to 29", the difference was 190 fps vs 205 fps. 
I would consider that significant. 

Viper1 out.


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## grantmac (May 31, 2007)

Viper1 said:


> Guys -
> 
> Just for the record: The arrows in the picture weighted approx 350 grains and 320 grains.
> Through a chronograph, from a 42# bow, drawn to 29", the difference was 190 fps vs 205 fps.
> ...


Going from 8.3GPP to 7.6GPP yielding a 15fps increase doesn't track with any other data I've seen.


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## granite14 (Nov 10, 2014)

I pulled points on a few of the V6 arrows, and the weight diff was still there in the shaft/vanes.

I was already going to borrow a chrono for this weekend, so we'll see what it says.

One data point I have from this week is that about 35-40grains per arrow heavier is at least an inch lower at 5 yards stringwalking. 

I would think that some of the recurve arrows would be enough to drop a ring or 2 at 50M.


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## chrstphr (Nov 23, 2005)

for what its worth, 

if you shoot a carbon arrow a lot, you will wear off the carbon near the point where it sticks in the targets. The arrows may start out all the same weight but will not weigh the same after some months. If spine is good, the arrows will still group great. 

10 grains wont matter variance wont matter.

Chris


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## dchan (Jun 29, 2004)

I'm not saying it won't make a difference, or even a significant difference. It's just very hard to quantify the difference based on weight alone. If the weight is made up only in the point, then you have a weaker shaft. If a lot of the weight is in the tail then you will have a stiffer shaft. Either changes the spine and will affect flight. Too stiff will often fishtail and the arrow will drop faster. too weak and there will be less energy transferred efficiently and there will be a loss of distance. Either might result in low arrows compared to a perfectly spined arrow.

Many years ago, there was a long article written in Archery Focus regarding the building of "balanced" arrows and how it's not only about the weight, but balance of the weight. ie heavy points should be paired with heavy nock inserts, etc.. It was emphasizing how much more important spine was compared to overall weight. Such that paring a light nock insert with a heavy point to get to the same overall weight would be more problematic than paring a lighter nock insert with a lighter point, and living with the slight variance in overall weight would be a better choice in order to maintain more even spine variance. 

In the example given in the magazine, the overall difference was about 4 gn from heaviest to lightest with the bulk of the arrows in the middle being within 1 gn of each other so it really was not much.

In Viper's example, While I agree just adding weight will lower FPS, we can't discount all the additional differences in the arrows to cause some of that arrow drop. (different vanes, possibly different spine or diameter of arrow, etc.)

In Chris' example,

I would suspect the amount of carbon we remove from wear on an arrow is pretty insignificant. Considering on a carbon arrow, an inch of shaft is somewhere around 7gpi and the amount of carbon we remove in wear is probably less than .5 percent of the material for about 4" of the shaft That's probably somewhere around .14gn. less than most grain scales can resolve. Even if we remove 1 percent of the material that's only .28 gn.

It's there and in theory it will have some affect but in the real world, if the arrows group together, don't worry about it and go shoot.


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## granite14 (Nov 10, 2014)

This is interesting stuff to me. I have seen 10gr point weight give me weak arrows. I do know that my arrows group, on the other hand, I've seen high and low perfectly vertical 3s when others are in the center. Usually I just chalk it up to not having a clicker.

Anyway, as soon as I find my clicker plate for my Gillo, I'm going to try some experiments on these and will number them as well. I've never numbered my arrows or paid any attention.


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## kshet26 (Dec 20, 2010)

In regards to balance, I wonder if it would make sense to take that literally. For example comparing the balance points across an assembled set?


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## Viper1 (Aug 21, 2003)

DC -

Here's the thing, when using a chronograph, you're looking a Vo, (basically at 5'). Unless spine is really far off, like enough to loose significant energy during paradox (and I doubt we're doing that), the only thing affecting Vo is weight. The 15 fps difference was pretty reproducible among different machines at different ranges over a number of years. 

This really isn't debatable, since anyone with a grain scale, chronograph and a range can test it out for themselves. 

BTW - for full disclosure, the vanes were the same (type and orientation) and I was comparing 600 C1s to X7 1914s. The diameter is different, but given other tests I've done, air resistance along the path of the arrow won't account for that kind of a drop. 

Like I said, I'm satisfied with my results, and I would suggest that if anyone is that interested, it's pretty easy to give it a go, rather than Internet quarterbacking. 

I do agree with you, that most of this is pretty meaningless, and sometimes it's better to just go out and shoot ...

Viper1 out.


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## Mr. Roboto (Jul 13, 2012)

I shoot 3-18 ACC's and I learned the hard way that from lot to lot there can be a big variation in weight. I finally got a reply from Easton about that. They say that they sort the arrows to be within 1 gr in the lot of the dozen you buy. But the 14gr difference that I measured in the new lot vs my old lot falls within the weight tolerances they have.


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## dchan (Jun 29, 2004)

Viper1 said:


> BTW - for full disclosure, the vanes were the same (type and orientation) and I was comparing 600 C1s to X7 1914s.
> 
> ---
> 
> I do agree with you, that most of this is pretty meaningless, and sometimes it's better to just go out and shoot ...


Thanks for the disclosure. I couldn't tell from the images. Looked like different vanes. Was pretty sure they were different arrows.

I don't doubt your findings. I am curious however about that large of a drop. I do know I gain about 3-5 fps just by using a tab over bare fingers when shooting lightweight bows. (I was surprised) so I do understand that some things we don't even consider can often change our expected outcome.

I wonder if the compression characteristics of the 2 different materials and weight distribution could be part of the equation. (for curiosity sake only) for as we do both agree, it's more important to go out and shoot. 

If an Aluminum arrow compresses easier than carbon or the other way around, and a heavier point on one over the other, you could have a change the efficiency of energy transfer and thus also gain/lose some velocity at launch. Just rambling. ..


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## Viper1 (Aug 21, 2003)

DC - 

I think you might be overthink this a little. Whether you're talking about arrows or race cars, it takes a lot of horsepower to overcome a little bit of weight. 
While all the things mentioned factor in to some degree, it's my feeling that within usable reason, weight affects Vo more than anything else. 

In a former life, I was a bit of a speed freak with bows, and the weight of the moving parts (arrows, strings and limbs, not in that order) always won out over just about everything else. Ditto on the race car thing 

Viper1 out.


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## dchan (Jun 29, 2004)

Fair enough Viper1, reasonable. 

Going back to the OP's original question. Don't worry about the weights but number your arrows and shoot them in random order. Don't make adjustments for which numbers shoot where. Just shoot them like they are identical.

Do it several times and plot their landings. Select arrows that group together and when you have a set of 9-10. Use those for your competitions. If you want to weigh them after the fact go ahead but group testing has always been the gold standard for culling arrows. 

A lot of the others here will actually do this with bare shafts before fletching.


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## ccwilder3 (Sep 13, 2003)

Viper1 said:


> DC -
> 
> I think you might be overthink this a little. Whether you're talking about arrows or race cars, it takes a lot of horsepower to overcome a little bit of weight.
> While all the things mentioned factor in to some degree, it's my feeling that within usable reason, weight affects Vo more than anything else.
> ...


Viper1, my experience pretty much mirrors yours.

A while back I spent the weekend with 9 bows and a pile of different arrows, playing with just about every variable I could think of. I went so far as to make up weight tubes so I could add weight to the back as well as to the front of the arrow to maintain spine and FOC.

At thirty yards, 10 grains equaled about one yard of drop out of a bow shooting 310 fps.


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## ccwilder3 (Sep 13, 2003)

dchan said:


> Fair enough Viper1, reasonable.
> 
> Going back to the OP's original question. Don't worry about the weights but number your arrows and shoot them in random order. Don't make adjustments for which numbers shoot where. Just shoot them like they are identical.
> 
> ...


Words of wisdom.

There is a neat little app call Archezupshot that makes plotting your arrows a breeze.


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## dchan (Jun 29, 2004)

10 grains = one yard drop? as in 36" from original impact? or one yard on your sight marks?

I can understand the one yard on the sight. That makes lots of sense.


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## limbwalker (Sep 26, 2003)

dchan said:


> John, did you plot arrow by arrow? Did you find that heavier arrows impacted lower than lighter? Was there a pattern?


I wish I could tell you. I think I was so gobsmacked by the fact I could shoot 50's with those wood arrows at 70 meters that I forgot to take notes.


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## ccwilder3 (Sep 13, 2003)

dchan said:


> 10 grains = one yard drop? as in 36" from original impact? or one yard on your sight marks?
> 
> I can understand the one yard on the sight. That makes lots of sense.


Start with a 350 grain arrow. Make a good shot into the target at thirty yards. Now add 25 grains to the front of the arrow and 25 grains to the back of the arrow for a total of 50 grains. Make a good shot with the heavier arrow at 30 yards. It will hit lower. Leave the heavier arrow in the target and shoot the lighter arrow from thirty five yards. It will bust the nock on the heavier arrow.

As the distance increases, the difference will increase. So you cannot simply add one yard for all distances. By the time you get back to sixty yards a 10 grain addition will be closer to a two yard difference.

What really makes this thread so interesting to me is that my first set of skinny shafts was VAP V3's. I purchased them specifically to shoot a full FITA. At 90 meters out of 11 arrows, one was out of the top of the ten ring and two were out of the bottom. This was plotted shooting each arrow 12 times. The lightest arrow was out of the top and the two heaviest arrows were out of the bottom. There was a 9 grain difference from lightest to heaviest. The 12th arrow was never fletched as it was 11 grains heavier than the next heaviest arrow. I think it must have been mislabeled.


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## dchan (Jun 29, 2004)

limbwalker said:


> I think I was so gobsmacked by the fact I could shoot 50's with those wood arrows at 70 meters that I forgot to take notes.


Nah, He's just that good. He felt the weight difference as he loaded up and his body just made the adjustment! :whoo:


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## limbwalker (Sep 26, 2003)

dchan said:


> Nah, He's just that good. He felt the weight difference as he loaded up and his body just made the adjustment! :whoo:


LOL. I wish! But I do like that story!


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## Mr.Poindexter (May 29, 2016)

ccwilder3 said:


> At thirty yards, 10 grains equaled about one yard of drop out of a bow shooting 310 fps.


I guess if you are looking at a 350 grain arrow, one could say a 3% increase in weight would cause that amount of drop. My arrows are coming in around 814 grains and I suspect a 10 grain variance won't be anywhere near that amount of drop, which (1 yard of drop) is significant by the way considering I am shooting what feels like rebar with fletches.


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## grantmac (May 31, 2007)

Mr.Poindexter said:


> I guess if you are looking at a 350 grain arrow, one could say a 3% increase in weight would cause that amount of drop. My arrows are coming in around 814 grains and I suspect a 10 grain variance won't be anywhere near that amount of drop, which (1 yard of drop) is significant by the way considering I am shooting what feels like rebar with fletches.


Why are you shooting such improbably heavy arrows outdoors?


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## granite14 (Nov 10, 2014)

ccwilder3 said:


> What really makes this thread so interesting to me is that my first set of skinny shafts was VAP V3's. I purchased them specifically to shoot a full FITA. At 90 meters out of 11 arrows, one was out of the top of the ten ring and two were out of the bottom. This was plotted shooting each arrow 12 times. The lightest arrow was out of the top and the two heaviest arrows were out of the bottom. There was a 9 grain difference from lightest to heaviest. The 12th arrow was never fletched as it was 11 grains heavier than the next heaviest arrow. I think it must have been mislabeled.


Well, we have a double 900 round this weekend (barebow recurve). Since I won't have a chance to group test these with numbers on them, I'll just take the 6 in the middle and hope for the best 

I think I'll also have to weigh the V1 shafts I have to see if they are better.

So you are saying that 9 grains variance at 90M is from the top of 10 ring to bottom of 10 ring? That's good shooting


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## granite14 (Nov 10, 2014)

dchan said:


> Fair enough Viper1, reasonable.
> 
> Going back to the OP's original question. Don't worry about the weights but number your arrows and shoot them in random order. Don't make adjustments for which numbers shoot where. Just shoot them like they are identical.
> 
> ...


thanks.


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## Mr.Poindexter (May 29, 2016)

grantmac said:


> Why are you shooting such improbably heavy arrows outdoors?


Sorry, I should have clarified that they are not for FITA. They are my hunting arrows - Easton Dangerous Game, full metal jacket. I wouldn't shoot them indoors unless there was a rhino in my living room. I was just using them as an example that 10 grains of difference would likely not be as much of an effect on a heavy arrow and could have a more dramatic effect on a lighter arrow.


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## Vittorio (Jul 17, 2003)

Pls note that for instance the "C" class on Easton A/C arrows grants them to be within 3 grains each other on full lenght shaft. Then break off points by themselves are aound 3 grains in tolerance. Combination means aorund 5 grains maximum, and this in theory can grant arrows to be within the 10 ring at 70 mt. But this rarely happens if you mix up 2 different "C" classes of arrows, even if close ones. Of course, poundage and finished arrow make a lot of difference in result. Same 5 grains have a different (percntage) impact on light short arrows than on heavy long arrows.


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## Mr.Poindexter (May 29, 2016)

Having tips with a +/-3 grain tolerance while the arrows are +/-3 grains as well will allow one to weigh them all separately and put the +3 arrow with the -3 tip to keep the overall weight the same. Of course, the spine and FOC might be a bit different but at least the weights can be identical.


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## Viper1 (Aug 21, 2003)

Guy -

It took 33-34 posts for someone to state the obvious? 

A 5 grain variance on a 300 grain arrow (1.67%) is more significant than a 5 grain difference on a 600 grain arrow (0.83%)? Really, who da thunk it???

DC's suggestion of numbering arrows and looking for consistent "flyer's" is an old practice started when wood arrows were the norm - yeah, that long ago. Even now, it's not a bad idea, just to differentiate shooter error from equipment error. 

If all you're arrows are going in the middle, you have nothing to worry about, just carry on. If you have fliers, either figure out why or just cull out the "bad" ones (if there's a consistent "bad one"). 

Starting with arrows that have a variance of 10 or more grains, even 5 or more, just doesn't make any kind of sense, not to me any way, since getting "better" arrows isn't that hard these days. If you're convinced it doesn't matter, that's great too. 

Given responses that are all over the board, the only real answer is to try it and find out for yourself. 
Sorry, this isn't rocket science, it's just common sense. 

Viper1 out.


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## gdrudd13 (Feb 16, 2016)

So I'm a little late to the thread, but the one thing that has stood out to me is that all the arrows are assembled which means you have far more components than just the arrow shafts with weight tolerances. I would be curious as to what the weight differences are as bare shafts. The shafts themselves have weight tolerances, as do all the other components. While individually they may be small, added together they might be a more significant amount, especially when combined with the weight tolerance of the arrows. To find this out would require completely disassembling a set of arrows, so in all reality it's not really a viable option.


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## dchan (Jun 29, 2004)

gdrudd13 said:


> To find this out would require completely disassembling a set of arrows, so in all reality it's not really a viable option.


Most archers that are really shooting at a level that would begin to want to "balance" their arrows is probably buying components and assembling the arrows themselves. So if they are concerned about overall weight variance, they should be doing this before assembly.


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## gdrudd13 (Feb 16, 2016)

dchan said:


> Most archers that are really shooting at a level that would begin to want to "balance" their arrows is probably buying components and assembling the arrows themselves. So if they are concerned about overall weight variance, they should be doing this before assembly.


That was concerning the arrows in question that are fully assembled as opposed to new arrows. For new, bare, shafts it wouldn't be a problem obviously.


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## toxoph (Mar 24, 2005)

dchan said:


> Fair enough Viper1, reasonable.
> 
> Going back to the OP's original question. Don't worry about the weights but *number* your arrows and shoot them in random order. Don't make adjustments for which numbers shoot where. Just shoot them like they are identical.
> 
> ...


Best advice in this thread!


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