Wood arrow spine suggestion

[JCJ]

I am not good at picking wood arrow spine and could use some advice.

I have a Great Northern Bushbow. It is marked 43# @ 26". I use a dacron string with wool silencers. The bow sight window is not cut to center.

 I have had my daughter observe me shooting the bow and I consistently draw 29" to back of riser.  

I'd like to shoot 30-30.5" bop arrows with 125 gr. field points,Woodsman broadheads.

I have a Great Northern strap on quiver attached.

I am thinking that a 55-60 spine arrow cut to 30.5" would be the correct spine.

I have some 30.5" 68-73# spine arrows and they seem too stiff with 125 gr. points.

Any suggestions appreciated.

[Tree Killer]

I'd shoot 50-55, but that's just me.

[Orion]

You're probably pulling in the neighborhood of 50# at your draw length.  The bow is cut 1/8-inch from center.  55-60#  should be a good fit.  That's where I would start.

[snag]

You're pulling 52# @ 29" with that bow. I'd go with the 55/60's all so. With cutting them to 30"-30.5" bop they will fly good for you.