need help with buck mark

[sks_shooter]

I just got a browning buck mark and was trying to take it apart to clean it, but I can't find an allan key to fit the hex bolt to remove the barrel. Has anyone else come across this or does anyone know what size allan key I need?
Thanks

 

[albsch]

Mine takes a 9/64 for the bolts on the rail and a 7/64 for the hex bolt on the barrel.

 

[rustysdream]

If your gun is brand new in box, it should come with the allan key. Mine was in a plastic bag stapled to the Instruction Manual.
The first time when I tried to remove the sight base, I found the front screw way too tight. I thought I would break the allan key or worse, the gun...