ok im fixing to purchase some lam. birch arrows.  i have a 65 g/n critter gitter 65@ 28.  i shoot a full length arrow.  im going to put 190grns up front.  so which would i need. in general terms. i can always tweak them.
thanks
dustin parker

any one?

You have not told us your drawlength or string material, or the riser cut of the bow; a lot is depending on those answers.

28" draw.  f/f not sure what type.  fairly narrow shelf

Man, find that dynamic spine calculator thread and download that. You'll be playing with options for way too long. I have only shot one arrow I matched up from it but it shot well and I've heard from others that it is close. give it a shot.

Critter Gitters are cut 1/8 inch from center.  Why do you want to shoot a full length arrow (30 1/2 or 31 inches to back of point) if your draw is 28 inches?  For the additional weight?  Regardless, 75-80 will be plenty in an 11/32 shaft, if you can find it.  May want to go to 80-85 if the shaft diameter is 23/64.

i just like a long arrow.

go to 3 rivers and buy their test pak

Download this excel program:

http://briefcase.yahoo.com/bc/hkg3sg1@sbcglobal.net/vwp2?.tok=bcCz6kcB3cFO.9ke&.dir=/Public&.dnm=Dynamic+Spine+Calculator+Rev3-20-09.xls&.src=bc

And run your numbers.  From what I can see for a 31" arrow and 190 gr pts, you will need 90# spine.

Check it out it FREE.

Mike

thanks wing nut, i will look at it. i never would have thought 90# spine.

Fortunately you have 2-3" wood to spare. That can reduce your spine to the 75-80 range.