Sako 85 rear sight screw replacement

[Stonia]

I know this is niche, but I don't see any gunsmithing sub forum here. I discovered the rear sight base on my Sako 85 Black Bear has broken off. The single mounting screw sheared. How that happened, I have no idea. Does anyone happen to know its specs so that I can find a suitable replacement? Any parts diagrams just list it as "rear sight base screw" with no specifics, and all sources seem to be out of stock. Thanks in advance.

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[mxgsfmdpx]

My old manual shows a Sako part number of S4446485. Is that what you're looking for?

 

[Stonia]

Maybe? The description is correct. I have a ticket out with Beretta, but don't really expect anything from them.

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[Stonia]

Spoke to Beretta CS....they can't even pull an individual part number for that (I gave them the one above). They can sell me the whole assembly for like $180. They have no way of contacting Sako directly. That all seems pretty crappy.

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[mxgsfmdpx]

Ouch, man. Since the Beretta acquisition it's been WAY worse.

Take that chunk of threads down to a hardware store and use their inserts to figure out the threads/pitch, then buy the right length/head type screw for it is what I'd do. Use some red loctite or a paint pen when you reinstall.

 

[Stonia]

So it does appear to be an M4 0.5 fine thread. As if that's not hard enough to find, it also has a narrow head diameter. Anything I can find in that thread pitch has at least a 7mm diameter head where this requires under 6mm to fit the hole. The search continues.

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[Kurts86]

McMaster Carr or Fastenal is where I would look for a specialized faster like that.

 

[Stonia]

This really seems to be a unique fastener. The head diameter on the pictured one is too large, for example.

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[Kurts86]

There is a pretty good chance you will have to grind a head diameter down to fit and grind the thread length to the correct length.

If you tap a piece of metal to that size you then thread the bolt in and grind it flush on a belt sander. Most gunsmithing sets provide that fixture but since it’s metric that will be a challenge as it will need to be custom made. A gunsmith or machinist would be helpful making the fastener you use.

 

[Stonia]

Thanks for all the replies. A surprise solution presented itself. I had send a non-warranty email to Beretta USA quite some time ago and didn't get any response. Yesterday a package from BUSA was in my mailbox. Low and behold Beretta sent be two Sako sight blade kits for free with no notification. For some reason they have that base screw included. I can only surmise that the email team is different from the phone CS, so I partially take back any negativity addressed to Beretta CS. Problem solved for now.