Heat temper question

[Friends call me Pac]

I'm working on bow #7. The first 6 were red oak boards and all ended in failure.  This one is a hickory selfbow. I had it pulling 50 @28" but wanted to take it one step further.  I read what I could about heat tempering the belly and did that last night.

I left it overnight to cool and put it on the tree and scale this afternoon.  The weight had jumped to 55 @ 28"  and the top limb was slightly out of tiller.  

I used my tillering gizmo all along the way but with the heat treatment the pencil marks are kind of hard for me to see.

My questions are:

Is the weight jump from 50-55 normal when heat treating?

Is there something else I can use that I can see better than the pencil marks for the final tillering?  I wonder if a craft store carries "white" pencils?

Bow specs are:
71" tip to tip
Hickory stave
no backing
shooting for 45-50 @ 28"  (Currently 55 @28" after heat treating)

Only said I had two questions and that's been exceeded so might as well pile another one on.  I've read a selfbow will loose a few pounds after shooting a while.  Shold I just leave it at 55@28 and let nature finish it up?  How much can I exspect to loose by doing this?

[Magnum in Ms]

I have heat treated a red oak and only added about 3 lbs. I am working on a hickory bow now and did a mild heat treatment on it and it went up about 5 lbs so it seams that hickory responds much better than some woods. You can get silver pencils at office supply stores ,should be able to see it on the treated areas.

[Magnum in Ms]

You may loose a little weight as it shoots in and final sanding.