Removing core of Master 930

[blueduck]

I have a 930, and to remove the core, you need to use a hex key to remove a bolt hidden under the shackle. Ive tried various hex keys, but none seem to fit

Would anyone know the dimensions of the one I need? I can't seem to find any posts about disassembling this lock either.

[Kaotik]

If the center of the hex bolt has a nipple in it, then it is a tamper resistant/proof hex bolt. The only way to get that off is with the tamper resistant/proof hex keys, which can be purchased at some local hardware stores or larger home improvement outlets.

[blueduck]

I think it's just a regular hex bolt. Here's a link to a pic of it:

[Shrub]

Looks like a 4-5mm or 3/16" ish,