Is there a difference in GPI between a 11/32 & 23/64
I shoot 53# with a 27" 11/32 arrow with 125gr heads and they weigh around 450 to 500gr. I would like to get up around 500 to 550. can I get there if I switch to 23/64 or do I need to add point weight with a heavier spine arrow?

Regards
Sticks

Both the Hildebrands and surewood guys are great to work with. If you know what your original shafts weighed, just let them know and they should be able to get you close to the weight that you want without switching diameter shafts.

Rick

Yes and no. It would seem reasonable that a larger diameter shaft would be heavier than a smaller diameter shaft, but if they have the same spine, the larger diameter shaft may not be as dense as the smaller shaft.  It will depend on the specific shafts that you get.  Some may be heavier, some may not. I have a bunch of 11/32" shafts that are all spined within 5#, but they have a range of nearly 90 grains (this is a couple hundred shafts).  If you are shooting cedar you may just try going to douglas fir or some other material that tends to have a heavier mass weight.

If I recall correctly, surewoods 23/64 shafts weigh only about 10grns more than their 11/32 shafts.  Surewoods in the 50-60# spine range should be around 400 grains bareshaft.  They'll pick out heavier shafts if you ask them as well.

you could also go with hardwood that will give you the additional weight and most hardwoods are really tough.

Surewood douglas fir comes in a pretty wide range of mass weights. On their site they have a section titled "Mass Weight". It will give you a range of weights in each spine group. If you call Steve and talk with him he will help you get what you need.
David

thanks everyone!!!!

On average, yes, the 23/64 will weigh more than a 11/32 for a given spine.  Wood can vary quite a bit in weight, some species more than others.  I've seem D Fir vary by more than 150 grains within a given spine.

For a 28" BOP arrow and 125 gr point, a 425 gr 32" shaft will get you a 550 or little less finished arrow.

They do not all weigh the same, even if the spine is held constant. Yes, 23/64" are heavier, on average, than 11/32". But the weight of each individual arrow shaft can vary greatly.

The last dozen arrows I bought without first weighing them myself had a difference of 138 grains from heaviest to lightest! That's the last time I do that.

We sell POC shafts. We spine and weigh every single shaft ourselves, and then put them in groups. Typically spine groups are within 1#, and grain weights are within 10gr. Often the sets are better than that. Give me a call or shoot me an Email if you are interested in cedar and I'll let you know what I have on hand.