Rear shock lower bolt hole dimensions

[Jethro66]

I've just had to drill out the bolt that secures the lower fitting of the rear sock absorber to the swinging arm. The shock refuses to move. It would appear that there may be some of the bolt material left inside the assembly which is fowling the removal of the shock. If anyone has access to a 2009 or similar rear shock, and can measure the internal diameter of the bottom hole that the bolt slots through to secure to the swinging arm, I'd be extremely grateful. It will give me a ball park figure of how much material I need to remove to release this S.O.B. Currently I have chased a 10mm Cobalt drill bit through and it looks like approx 1mm of steel left between 8 o'clock and 12 o'clock position.
Many Thanks in advance.
Jethro

[guest2360]

The bottom shock bolt for all types of rear strut is an M10 if that helps you at all. 

[Jethro66]

I have a replacement bolt for the shock. I would like to know the shock hole diameter to give me an idea of  how much material, if any,  I need to remove before removing the shock.