New (to me) bow is loving some stiffer spine

[GMMAT]

I was tuning the 50# limbs on my new (to me) bow this morning....and I started out with a bare shaft CX 150 (that's what I'm shooting out of my current 52# curve).

NO DICE.  Not even close.

I know this isn't "scientific", but I have some fletched 250's here....and I got true flight back to 40 yds.

I'm ordering a couple bare shaft 250's, today.....but I'm wondering why this bow apparently like a stiffer shaft than anything in its' weight range I've ever shot?  150's have always been OK for that DW.

Cut past center?  FF?  More efficient?  What is it?

Thanks.

I'm not going to be surprised if I need 350's for the 56# limbs.

[R H Clark]

I would assume it is because it is cut farther past center.

[Oregon Okie]

I am shooting 250's out of 50# and 350's at 56# but that is at 30 inch draw so that has some affect.

[GMMAT]

I started out drawing 28", but I'd say mine has gotten a little longer.  I'm getting ready to go to a trusted source and do some fine tuning.  I'll report back.

[James Wrenn]

Centershot more than anything else.On a bow cut past center enough with a rest I can shoot about any carbon if I use length for adjustment.I shot 400s with 125gn points at the star shoot with a 40lb bow and I only draw 26".I had 500s ordered but they shipped the wrong shafts so I just tuned the 400s.At the last shoot I was shooting a bamboo/osage and a buddy was shooting full length fat cx linecutters.I shot his bareshaft and it was too weak for my bow but was shooting out of his 54lb widow just fine at a 3" longer draw length.How we shoot has a lot to do with the spine we shoot.My buddy and I can switch bows and shoot them just fine as long as we use our own arrows.His arrows are much too weak for me even though I draw less on the bows.