Arrow length question

[grahambiel]

I’ve been shooting the same arrows for a pretty long time (older generation fmj) and am looking at building a new set. I plan on doing most of the build myself but would like to have them cut when I order them so I don’t have to buy an arrow cutter. Is there a true rule of thumb for how long your arrows should be?

Im a 28” draw and my current arrows are 26.5” from nock valley to end of the carbon which puts the front one inch in front of my limbdriver rest when at full draw. This is just how my pro shop cut them several years ago so I’m not totally sold that they’re the correct length. I read on an old post here that states that the “one inch past the rest” rule was because of how the arrows tune but I struggle with whether that would really make an appreciable difference in a drop away rest as long as they’re long enough not to pose a safety issue.

I’ll be increasing the spine in my new arrows as I want to add more weight to increase my FOC but obviously how long I plan to cut them will impact that as well. Any input from folks that have some data behind why a certain arrow length might be best? I’ve never had issues with safety of my broadheads coming back over the shelf but have had guys tell me that it’s not safe and that they should extend past the riser. Again, I don’t put too much weight in that as gospel either but would love to get thoughts from those on here before I start planning out my new arrows.

 

[madkaw284]

What bow are you shooting? Poundage, draw weight, draw length? How much total weight are you planning on putting on the front? All this information is needed to make an informed decision.


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[grahambiel]

I shoot an elite z28, 70lbs 28” draw. I’m planning on a total arrow weight of around 500 grains but am going to download the archery program to play around with to determine spine and exactly how much weight I can get up front. Right now I’m leaning towards axis match grades or black eagle rampages

 

[madkaw284]

Depending on how much weight you wanna put up front you will be good with a 300 or 350 spine shaft. Again depending on the weight upfront you’d be fine cutting the shafts at your des length or an 1” or so short. It’s hard to really just throw an exact number out there. You can play with the calculators, but don’t take them as the be all end all. If you have a well tuned bow and good form then you can get away with a little more.


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[Topo_trekker]

Arrows should spine out to where they’ll be cut about an inch in front of rest.

There is a couple reasons for this. I won’t go into it too deep but this is basically where they recover the fastest from paradox coming out of bow.


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[grahambiel]

Arrows should spine out to where they’ll be cut about an inch in front of rest.

There is a couple reasons for this. I won’t go into it too deep but this is basically where they recover the fastest from paradox coming out of bow.


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In this case, is 1 inch the magic number or is slightly longer ok? 26.5 gets me exactly one inch in front of the rest but was thinking of cutting new arrows at 27 for a little more wiggle room

 

[Topo_trekker]

In this case, is 1 inch the magic number or is slightly longer ok? 26.5 gets me exactly one inch in front of the rest but was thinking of cutting new arrows at 27 for a little more wiggle room

It all depends on how well the arrow is tuned with your setup. 27 could absolutely work as long as arrows not too weak. Are you following a spine chart?

 

[Mike Islander]

No paradox on a compound bow, right? So just spine up to 300 or more and you should be fine at 500 grains, or even a bit more.

 

[grahambiel]

It all depends on how well the arrow is tuned with your setup. 27 could absolutely work as long as arrows not too weak. Are you following a spine chart?

I'm using AA. With 300 easton axis, AA says i'd be "marginal stiff" for a 27 inch arrow with 175 grains up front (planning for 100 grain broadhead, 25 grain collar and 50 grain insert) for a total arrow weight of 493 and an FOC of 15.21.

If I bump that to a 125 grain broadhead it brings me to 518 total weight with an FOC of 16.92 and AA says 300 spines are "slightly stiff" on that setup. If I were to increase my arrow length to say 28.5, AA calls this setup "optimum spine" but also brings me to a pretty heavy arrow at 534 grains.

I could also do black eagle rampage 300s with 225 grains up front which shows optimum spine on AA using a 28.5 inch shaft and arrives at a total arrow weight of 503 grains and an FOC of 19.82

Any of the above seems ok but I wanted to make sure I'm getting the right arrow length to start and then I'll figure out what I need to do with my spine and point weight using AA.

I guess what I was trying to do is narrow down the proper arrow length first and then back into what spine I need based on the point weight I'd like to run

 

[Topo_trekker]

No paradox on a compound bow, right? So just spine up to 300 or more and you should be fine at 500 grains, or even a bit more.

Well it doesn’t happen horizontally like a trad bow shot with fingers. It does happen vertically with a compound and release. Don’t want the arrow to take off in the middle of a wave, it will bounce somewhat causing inaccuracies.


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[Topo_trekker]

To many things to consider when building your own, I get it haha. This is what you should prioritize. Total weight and length, forget foc. Sounds like youre on the right track with the Axis, 27”, and trying 100/125. The safety thing is really a non issue unless you’re a total beginner and don’t have a full containment rest. Once you get a bh on it anyways the point will be in front of riser.

Shoot for marginally stiff. Once you get a bh on the arrow, the extra resistance could make arrow slightly weaker so at that point you may be at optimum, depends on bh.

Shorter arrows perform better. They tune and shoot paper better and the vanes will take control and steer the bh and arrow faster.


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[Btaylor]

I shoot an elite z28, 70lbs 28” draw. I’m planning on a total arrow weight of around 500 grains but am going to download the archery program to play around with to determine spine and exactly how much weight I can get up front. Right now I’m leaning towards axis match grades or black eagle rampages

If you are cutting the shafts dow to 26.5-27" then I would just get the standard Axis. If you cut them from both ends you will almost always end up with a match grade shaft but you started at a lower price point.

 

[elkstabber]

I used AA and selected my arrows to be "marginally stiff". Then verified by shooting bare shafts up to 40 yards and now I couldn't be happier.

 

[grahambiel]

Thanks guys. I think I’m gonna go with the 27 inch 300 axis and test 175 and 200 up front to see which tunes best.

 

[bat-cave]

You might want to consider picking up some software to help you do the analysis. I'm very happy with Software for Archers. It's super easy to tinker and see the impact of arrow length, point weight, spine, adding wraps 3 vs 4 fletch etc ... Granted, I'm a geek and I love tinkering .. but I have learned a lot this way and it's translated well to my groups and animals in the freezer.