Arrow Spine Help?

[HawkeyeArcher]

Looking for some help from the tradgang!

Traded for a pittsley predator late last year and i'm just getting to tuning the bow. It's a 60" predator 50#@28" and i draw it to 30" wish should make it about 55# at my draw.

I started papertuning with some uncut 400's  - too weak. and too way under 10gpp as well.

Tried my uncut 340's through the paper with a regular aluminum inserts and 125gr field points - still showing feathers to the left - too week. and too light for me as well.

I looked at the dynamic spine calculator and it showed that my bow's dynamic spine is a hair over 77 and to get there with any significant weight, i should be looking at shooting 300 spine carbons. Does this sound right? seems really stiff to me, but i'd like to end up in the 575-600gr total arrow weight range.

FYI, this is my first recurve, and that may be why it seems to need the stiffer shafts compared to the longbows i'm used to.

Any help is appreciated!!!

[damascusdave]

I too draw in the vicinity of 30 inches at about 60 pounds but lately have come to the conclusion I am drawing more like 30.5 at 55 pounds...right now I shoot in my basement at about 12 to 15 feet most of the time which is a great way to tell what works in terms of spine...I alternate among up to 10 bows shooting both right and left handed...the main thing I have learned is never decide something will or will not work until you have tried it...my 60 pound left handed 1960 Kodiak that used to tune fine with .340 spine arrows now shows weak even with .300 spine since I put on a 10 strand padded loop fastflight string...sure enough when I put a .250 spine FMJ in the calculator it comes out bang on...just hoping to find a few of those expensive little things on sale to try out

DDave

[damascusdave]

A GT Trad 75/95 full length with aluminium insert and 3 4 inch feathers is about 400 grains and GT makes 50 and 100 grain inserts for them so that 575 to 600 grains is easily done...and of course Big Jim tends to have blemished shafts at a great price

DDave

[Orion]

If you already have a fair number of .400s and .340s, try building out the side plate a little.  No reason the .400s shouldn't work, even with more weight up front.  And the .340s should definitely not be too weak.