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 M1a Rear Sight disassembly
macman37  [Team Member]
10/15/2005 5:34:38 PM EST
I've got the green M1a book by Duff and am trying to take my rear sight apart because of all things, it's loose. I need to tension the sight cover, and I can't get the sight to come apart.

The book recommends turning the rifle on its left side and using a screwdriver to unscrew the sight and then the two knobs come apart, then you can use the aperture to lift the cover off.

Well, what happened when I tried unscrewing the knobs is the aperture came out. And I cannot get it back in. The knobs haven't budged, either... I have a rear-sight-less rifle now.

Thanks for any help,

jim
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Dano523  [Member]
10/15/2005 8:52:28 PM EST
Unscrew the windage knob inner bolt (ejection side of the rifle), then pull the elevation knob straight out (you may have to unscrew the windage screw a bit more as you pull on the elevation knob).

Hold the sight block, and screw the elevation knob counter clockwise to unscrew in from the block.

The real sight peep will pull straight up and out once the elevation knob is removed.

To get the tension cover off, you need to pry up and out on it to get it out of the rear receiverslot (to get it back in, use a screw driver on the very botom edge and push in until it seats back in the rear slot).

P.S. if you unscrew the peep out of the rifle with the elevation knob still in (unmodifed bottoming peep), chances are you just stripped the teeth off the elevation knob. Get the knobs out and see what kind of damage you did.
macman37  [Team Member]
10/16/2005 6:05:49 AM EST
Thanks for the info, Dano... I sure hope I didn't strip anything...

Dunno when I'll get back to working on it but I'll report back when I can.

jim
macman37  [Team Member]
10/16/2005 6:24:37 AM EST

Originally Posted By Dano523:
Unscrew the windage knob inner bolt (ejection side of the rifle), then pull the elevation knob straight out (you may have to unscrew the windage screw a bit more as you pull on the elevation knob).

Hold the sight block, and screw the elevation knob counter clockwise to unscrew in from the block.

The real sight peep will pull straight up and out once the elevation knob is removed.

To get the tension cover off, you need to pry up and out on it to get it out of the rear receiverslot (to get it back in, use a screw driver on the very botom edge and push in until it seats back in the rear slot).

P.S. if you unscrew the peep out of the rifle with the elevation knob still in (unmodifed bottoming peep), chances are you just stripped the teeth off the elevation knob. Get the knobs out and see what kind of damage you did.



One quick question: I followed the instructions in the book ... Namely, when unscrewing the windage knob inner bolt, it caused the elevation knob to turn at the same time- this is what caused the peep to come out... Should I hold the elevation knob tight and then turn the screwdriver?

Thanks for your time.
tangeant  [Member]
10/16/2005 8:21:02 AM EST
Hold the elev knob.

How I do it..

1. Turn wind knob and run rear sight base all the way to the elev knob side.
2. With thumb, push in the center of elev knob to relieve spring tension while unscrewing windage nut till loose.
3. Finish unscrewing windage knob from sight base and remove.
4. Pull out elev knob.
5. Pull out aperture.
6. Lift sight base and use a screw driver between it and recvr ledge ( where the index lines are ) and pop sight base and cover out.
7. Seperate base from sight cover.
Dano523  [Member]
10/16/2005 10:08:01 AM EST
Also, the elevation inner sloted nut will be tight, then loose, then tight, the loose.... it has a inner detent that locks it into a slot and keeps the inner nut from backing out.

When you put the sight back together, tighten the windage inner screw slot to slot until you can no longer turn the windage knob (locked too tight), then back off the inner screw one setting (1/2 turn) to allow movement of the sindage knob.
Note: the windage screw sets the tension for both the windage and elevation tension, so set it as tight as posable that allows the windage knob to still turn. Any looser and you chance the elevation knob of turning by it's self during live fire.
Ripcode  [Team Member]
10/16/2005 4:58:29 PM EST
Tagged
macman37  [Team Member]
10/16/2005 6:02:35 PM EST
Here's a question: Where do I index the sight to when putting it all back together?

Do I line up the index mark with the highest setting (with the peep extended all the way)? or do I run it down?

TIA... Hope to fix this Tuesday.
jim
Dano523  [Member]
10/16/2005 10:53:07 PM EST
Slide the peep about half way down, and install the elevation knob by pushing it straight in, and finish tightening the windage center nut without letting the knobs turn (don't worry where the index lines/number are).

Once done, run the peep all the way down, then bring it back up about 8 clicks. Now go re-sight the rifle back in, and once you have your meter zero, loosen the elevation center screw (don't let the knob turn), hold the peep still to rezero the knob settings, and tighten backup the screw (with the elevation screw loose, the knob will turn on the elevation shaft, you just have to keep the peep from moving).
macman37  [Team Member]
10/22/2005 7:54:02 AM EST
Nevermind!

Got it.

Thanks guys. Turns out all I needed was to put a screwdriver in the OTHER side to hold it steady and bingo, comes right out. Still need to work on the tension now- I disassembled it and then lightly tensioned the cover, and the rear sight peep is still loose once reassembled.

FWIW Dano it appears it came with a NM rear sight with a modified "tail" - it seems to work fine now that it's reassembled (except for the looseness I described...)

Thanks to all again.

jim
Dano523  [Member]
10/22/2005 8:06:53 AM EST
FYI: I'm not a big fan of side cant tensioning the cover to drift the sight to one side. It may work for service rifles, but is less than favorable for target rifles.

If you have side to side play, either peen the aputure, or replace it with a over size unit that needs to be stone/lapped for a tight fit.

www.m-14forum.com/showthread.php?t=13756
macman37  [Team Member]
10/22/2005 8:14:59 AM EST

Originally Posted By Dano523:
FYI: I'm not a big fan of side cant tensioning the cover to drift the sight to one side. It may work for service rifles, but is less than favorable for target rifles.

If you have side to side play, either peen the aputure, or replace it with a over size unit that needs to be stone/lapped for a tight fit.

www.m-14forum.com/showthread.php?t=13756



It's got up/down play as well...
Dano523  [Member]
10/22/2005 3:22:06 PM EST
Ok,
Side to side play is the aperture side rails loose in the main sight body slot (not making full contact side to side). Peening the aperture rails or just fitting a new one is one way, with cant pressuring the cover to drift the aperture over to one side a service correction method.

Up and down tracking play in main body is slop in the windage/aperture teeth. You can lightly peen the teeth of the aperture or the elevation knob to close the gaps and correct the problem, or just good quality replacements for the correct fit is the better way (read you can over peen the teeth and cause the two to strip out).

Rear/forward movement in the main body (not upward/downward tracking movement in the block) is lack of tension of the spring cover or if free play, often just the bottom of the aperture bottoming out on the receiver base can cause the problem. Either replace or tighten the spring cover, or if needed, relieve the bottom of the aperture past the teeth so it will not bottom out on the receiver.

As for the quick fix is someone hands you a rifle to try out and the aperture is swinging in the breeze, wrap a rubber band around the aperture and the windage knob to pin the little bastard to the right side (read solving the problem for you, and making him deal with the correct fix).
macman37  [Team Member]
10/22/2005 4:26:44 PM EST
Dano:

Thanks so much for your time! I think a "Band, Rubber, M1" will make its way onto the sight until my Fulton order comes in!

Thanks again,
jim
Dano523  [Member]
10/22/2005 7:59:12 PM EST
Jim, what is your location?

I'm in Denver and could just work over the sight if you can bring it by the house.
macman37  [Team Member]
10/23/2005 7:40:33 AM EST

Originally Posted By Dano523:
Jim, what is your location?

I'm in Denver and could just work over the sight if you can bring it by the house.



I'm in MI... If I had 2 weeks off work I'd drive over. Always wanted to visit that side of town.
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