the buggered hole at it's worst is 0.445, and only 0.232 away from the top. I'll go very slow indeed, and likely sand my dowel to not fit too snuggly, and pressure could split/crack the little bit remaining on the top wall.
Looks like I'll need to buy a walnut dowel online, and wait to finish my job. I could use oak or poplar, which the big box has, but I'd prefer walnut to maximize my chances of hiding it as much as possible.
EDIT: While I wait, I decided to check the inletting in the forearm. Wiped some jerrow's inletting black around the whole barrel (a little goes a very long way!), and gently put the action in, followed by handgaurd and bands. No black on any wood except the bedding area pictured below, and a smidge on the front band. I think there is room for improvement there after fixing the hole. that high spot in the right of the pic is causing the other side to contact that little spot on the band.
I went to double check since I didn't have the action screws in (which would change pressure)...and to my surprise there is no rear bushing! Good thing I've only put maybe 50 rounds through it tops. One is on the way.
Attachment 112313