Maybe because the 600 spine is too weak to begin with?

And the 500 spine is too stiff, thus the 250 -300 grain tip?

You need a 550 spine arrow:)

You are probably correct Roy! Not something I'm use to seeing, where would I find such things? Usually see in 100 increments?

The 550 spine was a joke:)

How long are the 600's, you could cut some off if there is extra shaft out front.

But 600 spine is leaning towards the light side for 40# I think.

I'm betting it is because the cherry riser is not cut as close to center....

""I do think the phenolic riser was cut past center, which I was not willing to do with the Cherry, it is just to center. ""

If that's the case, the 600s may be too stiff on the new riser.  You could be getting a false weak too from hitting the riser.

You will have to keep trying different stuff.

My bro shot arrows that were too stiff for a long time. I couldn't with same weight bow, his release was just better than mine. Got him to try my arrows and now he shoots way better than me. (Not really that hard to do )

Well Roy, you done sent me in a google goose chase, been looking at 550 spine!  Funny thing, they do exist, victory, blackeagle, and some others make them. But i gots too many R's to be buying more! Most all my arrows are 29", I draw 27", so little play. The black ones I shot are 30" and do best, so I'll stick with them. Those new fancy micro diameter shafts with outserts are nice, come in 550 spine, but price hurt my feelings! Especially with several dozen around here, and most bought for $40 per dozen. I watch clearance sales! 

Yep KennyM, that was my thought, false weak, been tricked by that! But I moved up in weight also on the 600's and it got ugly! Turned way left in rear and missed target on right! But I'm not a good shot either!  But I am persistent, or stubborn, in my efforts. Plus I got two dozen 600 spine! 

Add something behind side plate and try it.  Maybe the cherry is at fault... 

Quote from: kennym on May 26, 2021, 08:39:00 AM
Add something behind side plate and try it.  Maybe the cherry is at fault... 

Kenny has a point, that cherry might be making your shaft too weak.

Ain't touching that Roy!