Beretta 303/391 front sight thread size?

[yorgi]

I need to replace the original front sights on a Beretta 303(field) and a model 391(sporting) with Truglo "Fat Beads".

Does anyone know the correct thread size for the replacements? Someone told me that the correct size is 2.6mm , does this sound right? Thanks!

 

[beretta boy]

The popular consensus is 2.6mm, but I have also seen one reference to
a 3-56 thread screw as well. Being Italian, ( the Berettas, not me) I would try the 2.6mm as a "best bet".

 

[yorgi]

Grazie mille, beretta bambino!