I recently purchased some weight tubes from  three rivers archery in order to try and weigh down my arrow setup some more. I shoot a Beman ICS 400 full length with a 100 grain brass insert and a 125 grain point fletched with three 5 inch feathers.  I can get a pretty good tare (slightly weak) through paper with this arrow setup out of my Martin Hatfield at 60#.

I purchased the weight tubes @ 8 gpi and installed them as shown on the three rivers website.  I heard that adding the weight tubes will weaken an arrow shaft.  Upon paper tuning the new arrow setup i am getting a high (~3") and slightly weak (~1") tare. I cant move my nocking point down much at all, im pretty close to even as it is.

I plan on trying a lighter point without the brass insert and maybe a 340 spine ICS.  Im sure I will have to trim the shaft down a little no matter which one I go with.

Any advice would be greatly appreciated.    

Thanks,
Aaron

I added weight tubes to my 1916's, and found they made them a tad stiff, that's using the 3 gpi. With you using the higher weight tubes I would think they would be stiff.

I also found that the weight tubes "weakened" the dynamic spine in the Carbon Express shafts I was then shooting.  They also bounced back and forth enough to pop the nocks out when I shot a stump.

I know that you can get a false high tare produced by fletching contact against the shelf.  I did check the arrow by shooting multiple shots and then I tried my original arrow w/o the tubes with the same 'good' results, so i dont think it was my release causing the high left tare.

I have heard both results from different people.  I will try both weakening and stiffening the arrow with different point weights and trimming the shaft.  I'll play with the nocking point too I suppose.  

What is your draw length?

An honest 28" sir

I shoot a velcro rest and sideplate with a small peice of hard plastic under my shelf to slightly elevate my rest.

I would personally recommend that a shorter shaft and heavier point be ahead of weight tubes to up a carbon in weight.  I find excessively long carbon shaft to be odd to tune with heavy points.  

First though you have to get in the ball park on arrow tune.  You may be getting a nice tare in paper right now with your original set-up, but I think it is a false tune.  Not sure on your shooting distance and a lot of other things, but a full length 400 with 225 on the front in a bow that is 60@28 sounds way weak  to me.  Could be the weight tube is changing stuff just enough to show a problem with your original set-up.

I am tuning the arrows around three yards. The original arrow showed slighly weak and could stand to be trimmed a little, but not much.  I have shot this arrow outside with good light to inspect an funky movement on the back end of the arrow and it appears to be flying quite well. I will also be trying to tune using bare shafts vs. fletch shafts as another method.  I really liked the weight tubes because they seriously up the arrow weight, but if I cant make them work then so be it.

Try your original arrow at 6'in paper.  How does it fly bare shaft out about 20 yd or so?

I will have to get back to you on those ones.  I plan on doing some shooting outside tomorrow with the bare shafts.  I can check the shafts at six feet tonight.  Thanks for all the insight.

Aaron,

I have helped more than a few friends solve tuning issues by taking OUT weight tubes.  They do some funky things to an arrow IMO.  Had much better results with a heavier head and stiffer arrow.

I trimmed a half inch off the ICS 400s I have been shooting and left the 225 grains up front. I shot through paper at 6 feet and..... top two holes

I will shoot them outside and see how they fly at distance.  I still want to try the weight tubes in a stiffer shaft and see what happens but for right now  im happy with these arrows.