P72 Dovetail Screws

Discussion in 'Sako Rimfires and Small Action Rifles' started by Roadog, May 28, 2021.

  1. Roadog

    Roadog Member

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    Hello all , I’m looking for the 5 screws that hold on the factory Sako dovetail. I believe that the P72 an M78 screws are the same , not sure about other models, cause I don’t have them to compare too. Also was looking for the torque specs on them screws.
    An help would be greatly appreciated
    Thanks

     

  2. Roadog

    Roadog Member

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    Geez, these screws must be as scarce as hens teeth. I’m really needing some cause the previous owner over torqued them an smeared the threads on the screws. The receiver threads are fine just the screws threads are stripped off.
    Still looking for any kinda of help or ideas.
    Thanks
     
  3. stonecreek

    stonecreek SCC Secretary Forum Owner SCC Board Member

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    Yes, "original" screws for a P72/M78 dovetail would be almost non-existent. However, they are probably a standard metric thread, so if you'll take the best of one of your old screws to a fastener specialty store (or maybe even the screw bin at Home Depot along with an accurate caliper) you can probably find a workable replacement.
     
  4. Roadog

    Roadog Member

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    Thanks stonecreek , I’ve tried some local hardware store’s an 1 big box store an no luck yet. Didn’t know if maybe a gunsmith screw set from some manufacturer had them in the set.
     
  5. paulsonconstruction

    paulsonconstruction Sako-addicted

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    On the M78's I have had the best remedy for replacing the scope dovetail screws was to drill & tap the existing screw holes for the standard screw size used for scope base mounting. IIRC, it was either 6-48 or 8-40. I looked & looked for metric thread screws that would work but none have the correct head. Cheap, easy fix that solves the problem forever.
     
  6. Roadog

    Roadog Member

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    Thanks Paulson, As scarce as these screws are, I will probably end up doing that. I love the old Sako’s rimfires but boy ol boy spare parts for them is a bear to find.
    Thanks for the great idea
     
  7. marlin92

    marlin92 Well-Known Member

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    Does anyone have specs/messurements for them, I do have some odd and ends of Sako metric screws, but don't own a P72 or M78, so no idea what they look like or size. PRESUME they would be tapered flat head? Would the screws be the same as used for the finnwolf bases?
     
  8. Roadog

    Roadog Member

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    Marlin , I can get you the measurements of my screws but it will be tomorrow before I could get them to ya. I do have some pics I’ll post. An yes they are tapered flat heads. As far as the finnwolf screws not sure. I only have a P72 an M78
     

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  9. icebear

    icebear Sako-addicted

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    To determine the thread of the old screws, you need a metric screw thread checker. The one I have is called a "Metric Screw Chek'r" and is available from Brownells or Amazon. There's also one for American screw threads, and the latest version even has the odd thread sizes like 6-48. Everybody who works on guns should have a set of these anyway. If I remember right they are about $15 apiece and well worth it.

    I personally don't like to re-drill and re-tap holes on a receiver, or anywhere else on a firearm, unless it is absolutely necessary.
     
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  10. Roadog

    Roadog Member

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    Alright , got some measurements. I did the measurements in inches.
    Thread diameter = .135
    Head diameter = .255
    Total length did vari from screw to screw. But not worried about that, if longer I can cut down.
    Total length = .165 to .170
    I don’t have a thread checker. I’m guessing
    6-40 or 6-48 And also the Williams WGOS sight that came on it , those 2 screws thread into all holes on the receiver. But don’t know that thread size either. I tried calling Williams Tech line but no answer. Was thinking that maybe the Williams gunsmith screw set could have them in it.
     
  11. icebear

    icebear Sako-addicted

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    The correct screw for the scope rail on on a P72 is M3.5. I took the scope off mine and removed and measured one of the screws. Unfortunately, that size screws can be hard to find in the US, but some industrial fastener suppliers will have them in flathead form, as on the P72. I would recommend getting Allen or Torx heads rather than slotted.

    In general, any screw you find on a European rifle is going to be metric. If either a 6-40 or a 6-48 screw will go into a threaded hole, that's a red flag that neither of them is right. M3.5 is slightly larger in diameter than #6, so a #6 screw will thread into an M3.5 hole, but it will not hold tightly and the threads will be buggered. Fortunately, the steel in gun parts is usually much harder than the screws, so usually only the screws get damaged. You find this often on Sako scope rings. The ring screws are M3.5; owners or even gunsmiths will replace them with 6-48, which appears to work but if you take the screw out, you'll see the outer edge of the threads is shiny where it has worn against the threads of the ring. There's even a company that sells "Ruger/Sako Ring Screws," which cannot exist because Ruger and Sako threads are different. They are really Ruger screws that can be forced into a Sako thread, but that doesn't make it right.

    M3.5 is a screw size commonly used in European firearms, but I've hardly seen it anywhere else. A good hardware store will usually stock M3 and M4, but not M3.5. I've never found the correct cheese head and fillister head screws for the scope rings, but in my searches I have found more common head types such as flathead and pan head. You should be able to Google around and find some screws that will work on the Sako scope rail. McMaster-Carr or Grainger might be a good place to start. I've also seen M3.5 screws on eBay, but a lot of them are drop-shipped out of China so the quality may be suspect.

    And if you're going to be working on guns, you need a thread checker.
     
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  12. marlin92

    marlin92 Well-Known Member

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    Roadog sent message to you via conversation ( like PM )
     
  13. Roadog

    Roadog Member

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    icebear, thanks for the information an for removing your scope to check the screw size, very appreciated. I do need a thread checker, it’s on my list to get. I try to buy guns that don’t need to be gunsmithed, but didn’t turn out that way on this 1. I’m new to Sako an I didn’t think finding parts would be this hard, boy was I wrong.
     
  14. icebear

    icebear Sako-addicted

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    Sako parts are hard to find in any case, and the P72 and M78 were a sideshow back in the day. Remember, the L61R, P72, etc. have been out of production for 30-40 years or more and the company has been taken over by a conglomerate that has no interest in serving owners of older products. A Sako isn't like a Mauser, Winchester, Remington, etc. that there are a gazillion of them out there and parts are relatively abundant. Sad to say but that's the reality.
     
  15. Jeeps-And-Guns

    Jeeps-And-Guns Member

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    The screws are M3.5 x 0.6 threads. As for length, just measure them in MM with a caliper.
    I am missing one from my P72 and looked forever to find a replacement.
    I found a listing for ones online that are the right thread size/pitch, and the head design looks right, but I would have to buy 3700 of them for over 100-something dollars.
     

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