I am tuning a new to me R/D longbow. It is 52#@28" I draw a hair over 28". The bow is center cut with a maybe 1/16" thick strike plate. Dynaflight string. Brace height is set at 7.5" I have been testing some Easton gamegetters bareshafts and they are all showing weak flight. I use my phone with slo-mow to get an idea of how the arrows are flying. The only arrow I could get to fly correctly was a 30" Gamegetter 340 with 200grains up front. That seems like ot is way to stiff for the bow to me but maybe I'm wrong?
I'm an old guy so when you are talking about aluminum shafts 340 means jack to me. I'd say you need a 2016 or 2018.
It would be a 2315. I tried 2016 and 2117 and even with those the arrows consistently planed with nock left.
You'll get a better reading of the bare shaft if you fletch one and then cut the feathers back almost to the quill. Adding fletching stiffens a shaft, and having quills glued to the end helps to offset that effect. I would still want the bare shaft to show a little weak, because the whole feather will stiffen the shaft slightly more than the quills alone.
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I shoot them from heavier bows but 150-170 grain heads. 200 grains may be what is driving the good flight for the 52+# bow.
What's the make/model of bow?
It's an XRD it's made by a bowyer out of Alberta. Joe's Traditional.
Skinny string?
Insert weight?
Insert is standard rps insert around 15grains. The string is dynflight I'm not sure how many strands though.
I don't understand the angst. You found an arrow that tunes to your bow. Who cares what the spine calculator says.
I'm like Charlie. 2315 would be really stiff. I've found 2016 to be really versatile.
I was in the same boat as you, scratching my head!!
I shoot a very similar setup. Mine is 51@28 r/d longbow, cut past center. I ended up with full length CX 350's with an aluminum insert and 250 tips. They fly great! I too used my phone.
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I tried the 2016 and even with a 100gr point they planed left. The 2117 flew ok with 125 but by then my foc was not where I wanted it.
I have a R/D longbow that draws 59@28". My draw is only 25" so I am pulling pretty close to what you are describing. I find 2018 arrows to be just right. I think Charlie Lamb is probably right.
Maybe it's not to hard to see but that is a 2117 cut to 29.25" and 145 up front.
I shoot 30" 500 spine arrows with that much up front out of my rd longbow that is 52# @ just under 30". They all are different, and obviously differences in release and cant make a difference. That would be way too stiff for me. From your pic, it looks like you are very nock high, which will certainly change things compared to my setup, and hopefully isn't the result of shelf contact.
And all I can say is that a 400 spine shaft cut to 29.25" with only 145 up front would be way too stiff for me, contact the shelf, and give some pretty crazy flight.
But, as others have said, if you have good flight, why worry about it?
Might try raising your nock height a bit or for that matter, build the side plate out a bit and see if the other arrows start to fly right. I'm not much of a fan of center shot bows honestly.
did you try putting a toothpick behind the side plate to be sure your not torqueing the bow, because if I torque when tuning my arrows kick left ? Im sure you know you should be going nock right for stiff out of a RH bow all day long,,, Id say try 2" long 2016's with 125's or 1/2 to 1" longer 2018's with 200grs up front if its heavy R/D bow..
as far as FOC if you're bareshafts are flying straight and your POI is on wait till the summer to find a good FOC,, unless your not hunting now I wouldn't sweat the FOC for deer size game or smaller right now those arrows will be marking the first splatter I guarantee it....