Low wall tang screw size/pitch

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  • Last Post 10 April 2018
loophole posted this 09 April 2018

I have posted more than one question about the 85 low wall which I have converted from 32 rimfire to 32wcf.  I just got the thing shooting and decided to mount a tang sight to aid my aging eyesight.  I have sights made by Lyman, Marbles, and MVA, and I decided to use one I took off another rifle.  I just assumed the tang screw from a mod 94 (12-28) would work in the low wall.  I took the screw out of my pre 64 lever gun and it will not screw into the low wall tang.  The low wall seems to have a coarser  pitch.  I tried a few other 12-28 screws--none of them work.  The original low wall tang screw goes easily into the low wall tang,  and there is no sign of any alteration or damage on the rifle or screw.

I called the folks at MVA and talked to a couple of folks who said their tang screw for the mod 85 is 12-28, the same as a mod 94.  They make a high wall action with parts that interchange with the original, and the tang screw is a 12-28.

I have looked all over the net for something that will shed light on this problem, and the only thing I have found is that Marble's makes a screw set for its mod 85 sight (out of stock, no backorder) which has a different stock number than for a mod 94.  I have seen a bunch of adds for tang sights which fit mod 92's, mod 94's and other lever actions, but none which also fit a mod 85.

Once again, if any of you have any insight on this mystery, I sure would appreciate your enlightenment.

Steve K

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RicinYakima posted this 10 April 2018

Do you have a thread gauge?

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Pepe Ray posted this 10 April 2018

I don't mean to be redundant but have had a few strokes.

Is this for a Winchester M85 lo-wall? and are you looking for the side tang screw or the top?

I have Wisner's book of hard to find parts.

Talk to me.      Pepe Ray

Only in His name.

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Pepe Ray posted this 10 April 2018

 I'll never get used to this sit.  

If yhis is for a winchester M85 Lo Wall,  I have Wisner's Book of hard to find gun parts.

Only in His name.

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Ken Campbell Iowa posted this 10 April 2018

here is what i would do :

first find out about what size screw it should be .... probably a #12, #10, or #8 ... here are the number drill sizes that should slide in the existing threaded tang holes but not rattle very much ::

#12, 16 or 17 drill ......#10, 25 or 26 drill ....#8, 29 or 30 drill .   ace hardware probably wouldn't mind you playing with their drill bit selection if you bought something on the way out ...  at least they wouldn't when i was a kid ... hope nothing has changed ...

if #12, both #12-28 and #12-24 screws are available  .....

it also could be that 100 years ago they used a worn soft tap and it just needs to be refreshed with a modern tap of the same thread form .  with a dremel tool you can make a thread chaser from an extra screw for a two-time chase .   same if the existing screw holes are corroded or full of hardened shellac ...  or possibly the original tang was not factory tapped ??

i me myself if  new holes are needed i drill/tap  for   ( 8-32 ... )  quality socket screws that are available everywhere .

************************

just some thoughts ....

ken * 18 *

 

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loophole posted this 10 April 2018

Thank y'all for your help.  Am I the only one who has problems like this?

I don't have a thread gauge; I always have used a tap or another screw in place of a thread gauge, as I did here  Unfortunately, I was thrown off track by the fact that the shank on the low wall screw is about  .050" larger than a new Marble's 12-28 screw.  And larger than the standard size shaft for that screw.  After carefully examining the two screws I saw that the threaded portions are the same dia., and the pitch is the same, although the new 12-28 screw went into the tang only about 1-1/2 turns till it stopped, while the low wall screw went right in without any binding.  I carefully used a tap to "chase" the threads, and the Marble screw went in to the end of the threaded portion.  The new screw was for a mod 94, and it is about 1/4 " longer than the low wall screw but the threaded parts are about the same length--the mod 94 screw will not tighten on the low wall with a  Marble's  sight. 

In the meantime I got a reply from Lyman saying it doesn't make a sight for an original low wall and doesn't make any screws for it .  Even though the sight they sell for a mod 94 will work fine in a low wall with a shorter screw! I just saw an add in Midway for a Marble sight to fit an original low wall but is a special order item with a 6 week wait and an extra $50 over the price of the same sight they sell to fit a Japanese low wall, but with a different screw.  

Because of the bigger shaft on the original screw I had to do a bit if filing to make it fit the Marble sight,  and I had to drill out the hole in the sight to allow the head to fit.  Now I have a nice looking 32wcf rifle with bases for an MVA Winchester scope sight and a Marble tang sight adjustable for windage and elevation.

I hope this may help someone else who is trying to make a shooter from an old rimfire.

As an aside, I have 5 Mikoru mod 85's.  Each one has been an exceptionally accurate rifle, and very well made.  I have had a chance to compare the original John Browning  design with the changes made by those clever Japanese, and I cannot find one change which does not detract from the original.  It may be that hanging the fore end on the barrel may aid in getting maximum accuracy, but I would have to see that proved.  Most of the other changes simply add unnecessary  complexity and make it difficult to disassemble/assemble the rifle.

Steve K

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