.69 cal neck sizing die?

A bit out of the ordinary, but have any of you ever seen or heard of a .69 cal neck sizing die?
I will soon be picking up my greener police gun and will then start experimenting with converting some magtec 12ga brass into 12/14ga greener. I plan on loading it with Lee 7/8th oz Keydrive slugs for plinking I reckon, but making brass will be my first task.
They look like this foe anyone interested.

A brass shell with a slug for a bullet?

That is my plan yes

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I’m so aroused.

You’re not the only one

As with lots of things,I’ve looked into it lol.

You could make a neck sizer pretty easily if you were so inclined :grin:

@bentaz As it happens 0.69 = 11/16" well near enough
11/16" is 0.6875" Just need some all thread (7/8. - 14 ) and drill it out. And a bit of a hone.

Mmm on second thoughts that would be slug size, not brass size.