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  #1  
Old 01-07-2014, 12:18 PM
JeffWarner JeffWarner is offline
 
Join Date: Jan 2014
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Default S100 Sight Detent Ball

I’m trying to repair an S100 Sight that is missing the elevation Detent Ball (listed as part # S202 as “ball”).

http://www.box54.com/ex-s100.jpg

Can anyone point me to a suitable part … something else must use a similar size. Barring that, can anyone tell me the diameter of the ball? I figure a ball bearing of similar size would be an acceptable substitute.

From the parts list at the link, I know the windage uses a the same size dent ball as the elevation, but I was unable to disassemble it. Removing the aperture and cranking in a lot of left adjustment will unscrew the windage slide, but I was not able to see how the windage screw was being held in the bracket. If there is an easy way to get apart, I can use that ball for measurements.
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  #2  
Old 01-07-2014, 02:37 PM
Fishman Fishman is offline
 
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Location: Washington State
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Quote:
Originally Posted by poochie View Post
Jeff,
Click on this sight and ask your question there. Those fellows eat & sleep Mossberg stuff. In fact someone may give you the ball bearing you need. Good luck.
http://www.rimfirecentral.com/forums...splay.php?f=51
Poochie has ya headed in the right direction for sure. This link withen the sticky "Mossberg Technical Support" should answer your question specific.
http://www.rimfirecentral.com/forums...d.php?t=396366
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  #3  
Old 01-07-2014, 04:47 PM
JeffWarner JeffWarner is offline
 
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Quote:
Originally Posted by poochie View Post
Jeff,
Click on this sight and ask your question there. Those fellows eat & sleep Mossberg stuff. In fact someone may give you the ball bearing you need. Good luck.
http://www.rimfirecentral.com/forums...splay.php?f=51
Quote:
Originally Posted by Fishman View Post
Poochie has ya headed in the right direction for sure. This link withen the sticky "Mossberg Technical Support" should answer your question specific.
http://www.rimfirecentral.com/forums...d.php?t=396366
Thanks!

My Google-Foo is weak. While I'm a member of Rimfire Central....all the "hits" on Mossberg Sights looked to come back to CMP.

Good Gosh, an entire sticky on detent balls, how did I miss that!
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  #4  
Old 01-08-2014, 12:22 PM
presidentg presidentg is offline
 
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Location: Northeast Ohio
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The diameter of the ball is somewhere around .065", forgive me for not popping it out and checking more precisely. The ball is trapped by the elevation knob and yoke spring, as you already know. If you are handy with a drill, file and polishing stone find a drill bit of approximate size. Chuck it into the drill, drilly end into the chuck. With a file and the drill spinning round out the base of the bit. Polish shiny bright. Insert the rounded end into the sight base making sure the "ball" rests in a detent. Mark it and cut off the length you need. You'll have a tiny round nose bullet.
You could also use soft steel, like a nail, or brass rod which would be easier to work but wear a bit faster than hard steel.
If you have lots of old computer fans you may find a ball bearing the right size in there. Also a quick release hose fitting can be cannibalized for small ball bearings. Brownells offer "detent" ball bearings of several sizes but you have to buy a lifetime supply.

Windage arm: disassemble as you mentioned, remove the spring.
Look carefully, way down in there and you'll see a clip spring holding the windage screw in place. Imagine a square with a "U" cut out. If the sight is old and caked with gun cheese it's probably hidden. Don't loose it but if you do a small twist of safety wire will save the day.
Old .22s are wonderful old puzzles. Parts for many are impssible to find. Luckily most parts are easy to make with StoneAge equipment.
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  #5  
Old 01-13-2014, 10:30 PM
Flipseat Flipseat is offline
 
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Jeff, if you find something that works please post here about it. I also have an S100 in need of a detent ball.
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  #6  
Old 01-14-2014, 12:30 AM
GGaskill GGaskill is offline
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Maybe a 2 mm ball would fit well?
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  #7  
Old 01-15-2014, 04:54 PM
presidentg presidentg is offline
 
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OK, I've disassembled the sight and removed the ball bearing. The ball bearing measures .077", the hole in the sight base measures .075". The ball bearing is not a drop through fit, it takes a small amount of pressure to seat it in the hole.
2mm = .078" so perhaps it will work.
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  #8  
Old 01-15-2014, 07:06 PM
slickshot223 slickshot223 is offline
 
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Just rec'd some 3/32 balls which will work with a little effort--PM me your address and you will get a few in the mail.
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  #9  
Old 01-16-2014, 05:23 PM
JeffWarner JeffWarner is offline
 
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Quote:
Originally Posted by presidentg View Post
OK, I've disassembled the sight and removed the ball bearing. The ball bearing measures .077", the hole in the sight base measures .075". The ball bearing is not a drop through fit, it takes a small amount of pressure to seat it in the hole.
2mm = .078" so perhaps it will work.
presidentg - thanks for pulling yours apart and good suggestions on "alternative" sources. Using the chuck end of drill bits, I figured an ~0.08" ball would fit the elevation hole. 5/64" (0.078") was "GO" and 3/32" was "NO GO". This matches up to what Rimfirecentral had and I figure my best fit is a 2.0mm ball. http://www.vxb.com/page/bearings/PRO...Balls/Kit12060

Before I head down that road, I'm going to see what I have lying around in house in computer fan motors or what I can scrounge locally. I live in Houston, its the 4th largest city in the US ... I should be able to find bearings here!

Quote:
Originally Posted by slickshot223 View Post
Just rec'd some 3/32 balls which will work with a little effort--PM me your address and you will get a few in the mail.
slickshot - thanks for the offer (and the PM), but I don't think I can use the 3/32" balls in my base. I don't have a lot of extra "metal" around the hole, so I'm reluctant to enlarge it.

Quote:
Originally Posted by Flipseat View Post
Jeff, if you find something that works please post here about it. I also have an S100 in need of a detent ball.
flipseat - I'll post what I end up with. I might end up with a lifetime supply of 2.0mm balls and be happy to send them off! Double check your base diameter. The guys on Rimefirecentral have been enlarging the hole to fit 3/32" balls .. if you can do that, its probably the path of least resistance.
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  #10  
Old 03-13-2014, 09:11 AM
JeffWarner JeffWarner is offline
 
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Through the generosity of a forum member, I got my hands on some 2mm ball bearings ... and they worked perfectly! While the RimfireCentral "detent ball" master thread recommends drilling out the receiver to hold 3/32" balls, I'd recommend the 2mm since it was a drop in part for me.

I've had this S-100 sight for 25 years and I'm happy to get it back in service. I built it up from several broken sights and I can still remember the elevation detent ball skidding across the garage in oblivion. In the late 80's I shot on my High School's Government Sponsored Rifle Team ... since CMP wasn't around then, I can only assume it was a DCM program. I still get strange looks when I try to explain that there were guns at a school ... and it was ok!.

With 4 years of shooting every week, I got very familiar with the Mossberg M44 and I've been on the lookout for good one at a local gun show. I figure with a working sight in my possession, I can get a better deal on a rifle missing its original S-100.
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