I'll be the dissenting voice when it comes to the Zanardini 9lbs 6oz Double being too light for a .470...

Plenty of .458 win mags were made and used in that weight range.

Fit is everything though...

They are local to you, if you otherwise like the gun it would be worth seeing if they will let you run a 5 pack of ammo through it at a local range if you spring for the ammo, to see if it fits you good enough to handle the recoil.

For a potential 18K sale I don't see how they could say no...

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