Hey all,
Have a quick question...shooting a 55# bow; I am shooting Carbon Express Rebels with 400 spine. When I put in a 50 grain insert with 170 grain point they fly like darts.
:banghead:
WHY? :campfire:
The 170 grain point makes the spine act weaker because its farther out on the shaft.
That's right! Just like making the arrow longer.
moving the weight forward 1/2 an inch makes that much difference?
Not sure how long your shafts are, but I'm using the CX Terminator Selects .397 in my 53# Griffin and these shafts are loaded up with 385 grains. I have cut the shafts to 29.92 BOP, 30.2 BOP and Full Length 32.874 BOP and they all shoot to the same place!
Load your shafts up with more weight and see what they will do. The more weight I added the better they shot.
I just posted my finding "More EFoC and Carbon Arrows".
Mike
shoot the 50 grain insert and the 170 grain head.
If you are using the standard brass 5/16 inserts the 50 gr. inserts are also shorter than the 100's. So not only are you moving the weight back, but you are also shortening the shaft a little and making it stiffer.
Yes, 1/2 inch can make a big difference. Particularly since the 400 spine shafts are acting like they are overspined for your bow. I would try adding more weight up front. I bet they will fly even better. You might want to consider trying some 500 spine arrows.
What Xtrema said, that 100g is almost 2x longer, reducing the flexable length of the shaft thus stiffening it.
Eric