Working on Rear Sight Assemblies - M14 Forum

M14 Forum


Working on Rear Sight Assemblies

This is a discussion on Working on Rear Sight Assemblies within the Gus Fisher forums, part of the Gun Professionals category; Part I – Checking Rear Sight Assemblies Folks, there is a good bit of “Ye Olde Art and Mysterie” about working on rear sights than ...


Go Back   M14 Forum > Gun Professionals > Gus Fisher

16Thanks
Reply
 
LinkBack Moderator Tools Display Modes

Old January 2nd, 2010, 04:33 PM   #1
MGySgt USMC (ret)
 
Gus Fisher's Avatar
 
Join Date: Nov 2008
Location: Virginia
Posts: 7,066

Awards Showcase

Working on Rear Sight Assemblies

Part I – Checking Rear Sight Assemblies

Folks, there is a good bit of “Ye Olde Art and Mysterie” about working on rear sights than many folks imagine and it is not an exact science nor a simple matter of replacing parts to get them right. What makes it even more difficult is that no commercial receiver is totally correct in the rear sight area. Even when you have a correctly milled rear sight area as on a REAL G.I. M14 or M1 Garand, there are still enough tolerance differences or tolerance stack up that can cause you problems. Also, there is no way a fix for one Rear Sight (RS) will automatically fix a problem with a RS on a different receiver.

The first thing I do when inspecting a real M14, M1 Garand or any commercial M14 rifle is to grab my pair of Brownell’s Magazine Tube/Cap Pliers. These have hard rubber like pads that will hold the pinion drum securely without damaging it. You could also wrap thin leather around the pinion drum and grab them with slip joint pliers. Then I use a screwdriver with a tip that matches the slot in the nut in the center of the pinion and try to tighten it. Usually, I find these nuts somewhat to very loose and that’s bad as they need to be tight. Sometimes all you have to do to fix a problem rear sight is to tighten this nut. I’ve also been informed the Brownell’s pliers were actually some kind of automotive pliers, but I’m not sure as I’m not an auto mechanic. Anyway, here’s a link showing these pliers.

http://www.brownells.com/.aspx/pid=1...UBE_CAP_PLIERS

Once you know the nut in the pinion is tight, it is time to check the windage knob to see if you can turn the knob. If it is too tight or too loose, then the nut in the windage knob may not be tightened correctly. What I have found to be the “sweet spot” for most sights is that when you tighten this nut, the first time it JUMPS into position is most often the correct amount of tightness. I sometimes go one more half turn when the elevation pinion has a worn triangular projection or the spring tension in the pinion is worn. If that causes the windage knob to be too tight, then you need to back off the nut to the first setting. SPECIAL NOTE: I have used this extra click of tightness on windage knobs that make it a little difficult to turn the windage knob to save the person from having to buy a new pinion. If WHILE you push inwards on the nut in the elevation pinion and at the same time then can move the windage knob, that may save you from having to buy a new pinion for a while. It isn’t as convenient as just turning the windage knob, but it saves you rather big bucks on a new pinion.

The next thing I do is run the aperture up about 10 clicks to see the clicks are solid and consistent. Then I leave the aperture there. I use my thumb to press downwards and forwards on the aperture to see if the aperture will slip and slide downward. Now A CAUTION HERE: On even the most perfectly fitted and working RS assembly, if you use enough pressure, you CAN AND WILL force the aperture down. That is NOT a valid test. If the aperture slips with very little pressure, you can try tightening the windage knob one more half turn. If that doesn’t fix it, you may be able to fix the problem with a tighter fitting rear sight cover, but you may also need a new elevation pinion. If that extra half turn on the windage knob does fix it and if now you can not move the windage knob, again you may need either a different rear sight cover or a new elevation pinion. On NM RS apertures, I run the aperture up to 30 clicks and try it again as NM shooters will often use that much elevation.

The next check is to turn the windage knob 12 clicks to the right and back to zero than 12 clicks to the left and back to zero. (24 clicks each way with NM Ĺ minute windage knobs.) This ensures the RS base moves correctly and comes back correctly according to the hash marks on the receiver. If the windage knob is too hard to turn or skips or catches, then a different RS cover is often in order OR you have problems inside the receiver.

The next thing I check is to push in on the right and then the left side of the RS base. You want the RS base to either not move or spring back when you release tension. This was not considered absolutely necessary on a G.I. rifle, but it makes for a more consistent rear sight adjustments. If it does not pass this test, usually you need a different RS cover.

There are additional things we check on NM RS assemblies, though that can go to a full book length to explain and really is too involved for anyone but an Armorer or Gunsmith.

Thanks from Deacon, budster, m14nm and 1 others

Last edited by Gus Fisher; January 2nd, 2010 at 11:31 PM.
Gus Fisher is offline  
Remove Ads
Old January 2nd, 2010, 04:49 PM   #2
Platoon Commander
 
Join Date: Nov 2009
Location: Edgewater, CO
Posts: 524
WOW. That's all info we can really use, right now - without beacoup expertise. Nice job.

DaveH is offline  
Old January 2nd, 2010, 05:12 PM   #3
MGySgt USMC (ret)
 
Gus Fisher's Avatar
 
Join Date: Nov 2008
Location: Virginia
Posts: 7,066

Awards Showcase

Part II

Inspecting Rear Sight Parts

The first part to inspect is the elevation pinion. After tightening the nut, you want to look at the condition of the triangular projection on the inside of the drum. That engages the serrations on the left side of the receiver. If that triangular projection is rounded over or worn down a lot, you have to replace the pinion because it won’t give you good clicks of elevation. There are some people who are rewelding and recutting these projections, but the cost is now more than a replacement pinion.

You can't really tell by sight if the windage knob will work correctly unless it is obviously damaged. I’ve only run across a half dozen windage knobs that had the “C:” spring worn too much in over 35 years of working on these rifles.

On apertures the first thing to check is to see you have a good ROUND hole in it. If it is dinged or malformed, it is really better to replace it. Aperture sights work because the greatest amount of light coming through them is in the middle of the hole. If the hole is not round, that will throw your eye off even if you don’t realize it. I also prefer to use apertures that fit as tight as possible side to side and still move freely – even with standard G.I. sights. I measure the width of the apertures and the grooves in the RS base for them to ge the ones with the least amount of slop between these two parts. Now, they didn’t worry about that on G.I. M14’s or M1 Garands, so it is not absolutely necessary, it just makes the RS a little better. I know of no one who will sell you a different standard RS aperture by width, but if you go to Gun Shows and take a pair of dial calipers or micrometers, you may find a wider one than you now have.

You basically check the RS base for obvious damage or cracks. They are actually a very strong part and only very unusually do you find something wrong with them.

As to the RS cover, we have to remember it is a large spring. About the only thing you can look for is the condition of the indent that bears against the top of the RS aperture slide. You turn it upside down to check it. I prefer ones that are not gouged in the center of the “dimple” as that can cause problems when you move your windage knob side to side. You can’t look at them and tell if it will fit correctly, or if they are too tight or too loose. NOS RS covers CAN have too much tension for commercial M14 receivers due to the way those receivers are milled for the cover and base. That’s important to remember. I’ve seen NOS RS covers that froze up the RS assemblies HARD on commercial receivers. So it is best not to throw away a RS cover as many will fit correctly on some other rifle.

Thanks from Deacon and budster

Last edited by Gus Fisher; January 4th, 2010 at 11:13 AM.
Gus Fisher is offline  
Old January 2nd, 2010, 05:54 PM   #4
Old Salt
 
Riflenut's Avatar
 
Join Date: Jan 2005
Location: Ohio - Good Old USA
Posts: 1,056
MGySgt Fisher,

Thank you for taking the time to share your expertise.

This series needs to be saved as a sticky for future reference, as it is something that needs to be checked on every rifle!

Riflenut is offline  
Old January 2nd, 2010, 11:34 PM   #5
MGySgt USMC (ret)
 
Gus Fisher's Avatar
 
Join Date: Nov 2008
Location: Virginia
Posts: 7,066

Awards Showcase

Quote:
Originally Posted by davecampperry View Post
The next check is to turn the elevation pinion 12 clicks to the right and back to zero than 12 clicks to the left and back to zero. (24 clicks each way with NM Ĺ minute windage knobs.)

Gus, you meant 'windage knob' rather than 'elevation pinion'. Obviously just a pencigraphical error. dave
OOOPPPPSSSS.......... Thanks for figuring that out and posting it. I just changed it. Thanks for the excuse, but I missed it pure and simple.

Thanks from budster
Gus Fisher is offline  
Old January 3rd, 2010, 01:03 AM   #6
MGySgt USMC (ret)
 
Gus Fisher's Avatar
 
Join Date: Nov 2008
Location: Virginia
Posts: 7,066

Awards Showcase

Part III

Some of you have read that I was the Instructor of OJTís (On The Job Traineeís or Apprentices) and later on the NCOIC of the NM Rifle (M14) Rebuild Section at the Rifle Team Equipment Repair Shop at Quantico, VA while on active duty. I didnít come from a metal working background when I came to the RTE shop for my one year OJT program, so I had to sweat some blood to catch up or work things out. (For example: It was NOT pretty watching me figure out how to hand file metal flat. Grin. But, when I figured out how to do it, I could teach it to others so they would better understand.) That actually made me a better Instructor as I could understand the difficulties my OJTís were having and it caused me to look for ways to do things in an orderly approach.

I mention this because instead of using a ďshotgunĒ approach to working on rear sights where I give examples of ďIf this is wrong Ė try this, that or something else,Ē I believe it is far better to go through the whole RS in a systematic approach. That way you can identify and correct things as you go and you will better understand how everything is supposed to work. However, Iím also sorry to say that sometimes you have to go back and change something when further along in the process you find something wrong. IOW, donít expect that changing one or more things will automatically give you a good to great RS. You have to use patience to work RSís and sometimes you just have to have the stubbornness of a Mule and not give up to get them right.

SPECIAL NOTE: Over the last 35 plus years of working on commercial receivers, I have learned the HARD WAY that the very first thing to do on a new/bare commercial receiver is to try to fit the RS. If the RS area of the receiver is screwed up badly, then the receiver goes back to the factory as long as there is a warranty on the receiver. On a few commercial receivers over the years, I built the rest of the rifle first and did the RS as one of the last things like we did on REAL G.I. M14ís and M1ís. Well, a few commercial receivers were so bad there that I had to strip the receiver down and send it back Ė thereby wasting a lot of building time on those receivers. So by doing the RS first, you may avoid some serious problems.

Trust me, Iíve learned it saves time to go through the following procedures when working on commercial receivers and will go through these techniques when I have a problem with the RS on a REAL G.I. M14 or M1 Garand.

OK, the first thing is to either start with a bare receiver or take the whole RS assembly off the receiver. Orientation of the receiver for this whole procedure will be the front of the receiver pointing away from you and in the upright position, the same way it would be on a rifle when you fire it. To disassemble a RS, you first loosen the windage nut until it just spins and you can pull the elevation pinion out from the left side of the receiver. Then unscrew the windage knob until it comes free of the RS base and pull it out the right side. Then take a screwdriver and force it in place under the bottom rear of the RS base and between the RS base and receiver. Pry up on the screwdriver until the RS Base and RS cover pop out as a unit. Pull the aperture up and back it out of the rear sight base. Then the Base and cover will come apart in your hands.

I bought a ĺĒ wide, triangular, Medium India stone years ago to use for RS work. The reason I bought the triangular or ďThree Square StoneĒ as it is also called, was it was cheaper than a square stone, not because the triangular shape is better. So if you find a square stone instead, thatís fine. What I do is lay the stone all the way up into the RS base area on the receiver. I keep it flat and go forward and back and side to side for a few strokes each way. Iím not trying to remove any metal. What Iím doing is to polish the surface the RS base moves over and to see how flat and even the surface is. This because the RS base is going to move side to side over this area and you want that surface to be pretty flat. Even on G.I. receivers, you will see milling marks there and thatís no problem. What we donít want is high spots in the very front of the milled out area as that can/will cause the aperture to tighten up or freeze up too much and we donít want the very rear of the milled out cut to be high as that could cause the RS base not to travel smoothly. Even on G.I. receivers, this surface will not be and doesnít have to be perfectly flat and smooth.

Now, I canít tell you how many times over the years Iíve seen problems with this surface on commercial receivers. Iíve seen high spots on the front and rear and high spots to the left or right sides. In worse case scenarios, Iíve had to use a stone or diamond file to flatten the high spots and get the surface more even. You can use the ĺĒ wide stone to level things up, but if it takes more than you can flatten with 20 or 30 strokes of a stone Ė it is time to return the receiver/rifle to the factory or take it to a real M1/M14 Armorer. I can not and do not recommend the average person use a diamond file to flatten this area as you can ruin a receiver.

The next step is to put JUST the elevation pinion and windage knob in place through the holes of the receiver ďears.Ē Iíve actually seen receivers over the years where the holes for these parts were too small or off angle. Usually such problems can be fixed by a knowledgeable Armorer or gunsmith enough where the RS will work correctly. Tighten the windage knob until the nut JUMPS in place as that is the sweet spot. What we are checking is the serviceability of your elevation pinion and windage knob. If you get good, noticeable and even audible clicks when you turn the elevation pinion, thatís what we want. If you donít, then itís time to look at the triangular projection of the elevation pinion and the receiver serrations. If the pinion and windage knob are good, you can NOT fix the receiver serrations. You may have an elevation pinion where the spring inside is worn too much and a substitute pinion will work. If that doesnít work, then try a different windage knob. It those donít work, that would cause you to send the receiver/rifle back to the factory OR you can use a set of WWII M1 Garand Lock Bar sights on the rifle. Over the years, Iíve seen about a dozen commercial receivers where you had to use Lock Bar sights to get a useable RS. That was the only choice when the factory warranty was only good for a year or no factory warranty for whatever reason. NOTE: There is no warranty on the Chinese receivers, so using a set of WWII Lock Bar sights may save your bacon with some of them.

OK, with the elevation pinion and windage knob working or replaced, it is time to go on to the next thing. This post has gone on long enough, so I will write more in the next post. Stay tuned.

Thanks from Deacon and budster
Gus Fisher is offline  
Old January 3rd, 2010, 01:26 AM   #7
MGySgt USMC (ret)
 
Gus Fisher's Avatar
 
Join Date: Nov 2008
Location: Virginia
Posts: 7,066

Awards Showcase

OOps, a P.S. to my last post.

When the holes in the receiver for the elevation pinion and windage knob are too small or "cattywompous," you can usually fix them with a FINE sanding cartridge roll in a dremel tool used very carefully. What I do is put a layer of Dykem blue all around the holes and see where they are binding - by where the blue dye is worn off. A little polishing with the fine cartridge roll or a cratex point is done and you try and check and try and check until the holes are corrected.

Thanks from budster
Gus Fisher is offline  
Old January 3rd, 2010, 01:20 PM   #8
Lifer
 
Join Date: Oct 2006
Location: Chesterfield, VA
Posts: 3,615
What am I hurting on my rifle???

I ask because what I've been doing (just once after sighting in at 25 yds) is counting the clicks to full bottom, loosening the screw in the elevation knob, setting the elevation knob so it lines up (yards wise for 250 for my BSZ) and then snugging up the screw while holding the knob and then using the screw driver to tighten up the screw after the knob turns around to the full up position.

Is this damaging the teeth on the sight or the pinion? Thanks.

M1A's r BEST is offline  
Old January 3rd, 2010, 01:23 PM   #9
MGySgt USMC (ret)
 
Gus Fisher's Avatar
 
Join Date: Nov 2008
Location: Virginia
Posts: 7,066

Awards Showcase

Quote:
Originally Posted by art7 View Post
In a shameless plug for my own product, I sell rebuild kits to replace hoods on a MN sight. If that little C clip comes unwound (usually during a match),
Art,

Got a chuckle out of that statement about a shameless plug. $15.00 for the whole kit is cheap insurance if you shoot any kind of matches with a hooded rear sight. I would recommend anyone who competes with them get one of these and put it in your shooting kit.

Why do I say that? Well, we could have used one at Camp Perry just last year. The comedy of errors began when a good buddy and Distinguished shooter friend of Mike Gingher and mine decided at the last minute to put NM sights on his M1A to compete. (Don't even get me started on the lack of wisdom about waiting till just before a match to change sights. Grin.) Anyway, I had one set each of fitted .595 and .520 NM apertures and RS bases. Mike and I suggested the .595 sights due to the our buddy's age. Well, they are out zeroing the rifle the morning before the match and guess what? Our buddy bumped the hood on something and it popped off. Now Mike and I have replaced many hoods on RS hooded apertures,but he didn't have a tool with him. I'm back in the Armalite Booth with the tools, but they really didn't have time to come back, get it fixed and go back out. So they installed the .520 aperture and hood. Well, it was a bit too small for our buddy's eyes and it would have been better had he or Mike had one of these kits to repair the .595 hood and get a good zero with it.

Oh, and Art is correct that sure as shootin when something goes wrong with a NM hooded aperture, it is almost always in a match or when you really need it. Murphy ensures that.

Thanks from budster
Gus Fisher is offline  
Old January 3rd, 2010, 01:32 PM   #10
MGySgt USMC (ret)
 
Gus Fisher's Avatar
 
Join Date: Nov 2008
Location: Virginia
Posts: 7,066

Awards Showcase

Quote:
Originally Posted by M1A's r BEST View Post
What am I hurting on my rifle???

I ask because what I've been doing (just once after sighting in at 25 yds) is counting the clicks to full bottom, loosening the screw in the elevation knob, setting the elevation knob so it lines up (yards wise for 250 for my BSZ) and then snugging up the screw while holding the knob and then using the screw driver to tighten up the screw after the knob turns around to the full up position.

Is this damaging the teeth on the sight or the pinion? Thanks.
No, you should not be damaging the pinion as long as you hold the drum of the elevation pinion with something that won't mar or crack it - while you loosen or tighten the screw. If your fingers are strong enough to hold the drum, then you are in tall cotton. Most folks' fingers aren't strong enough to hold the drum securely enough to do that, though.

BTW for the folks who don't know, this is basically how you use the engraved and numbered hash marks on the elevation pinion drum to get a basic zero on a rifle - as the pinion was designed. Then if you had to shoot at longer ranges, you were supposed to move the elevation pinion to the higher engraved and numbered hash marks. In reality and in the Marine Corps, we didn't use the hash marks on the elevation drum. We kept track of how many clicks of elevation were used for each yard line. In combat, we set the sights at a BZO of 300 yards and just held high for longer ranges.

Thanks from Deacon and budster
Gus Fisher is offline  
Old January 3rd, 2010, 02:10 PM   #11
Platoon Sergeant
 
hueygunner's Avatar
 
Join Date: Aug 2002
Location: NEWBURGH NY
Posts: 304
pliers

gus:
those pliers are an esstential item for most aircraft mechanics.
they are for cannon plugs found on airframes engines and avionics and instruments.
technical name as per aviation types as well as dod types are pliers soft jaw cannon plug.
you can get them cheaper on ebay or right from any aircraft tool supplier.
gus you are a most knowledgeable guy and your posts are spot on. regards jeff shapiro hueygunner

Thanks from Deacon

Last edited by Hawk; January 3rd, 2010 at 04:54 PM. Reason: edited to conform to board policy
hueygunner is offline  
Old January 3rd, 2010, 02:46 PM   #12
Lifer
 
m1a shooter's Avatar
 
Join Date: Feb 2007
Location: Houston Texas
Posts: 2,570
Thanks Gus, who needs tech manuals when we have the experts here at our fingers.

m1a shooter is offline  
Old January 3rd, 2010, 07:08 PM   #13
Site Sponsor
 
ShootingSight's Avatar
 
Join Date: Jul 2004
Location: Cincinnati, OH
Posts: 2,685
Gus,

Send me your address,and I'll send you out a repair kit to keep in your shootig bag. Having the kit is a great way to guarantee that no sight will ever come apart again.

Art

ShootingSight is online now  
Old January 3rd, 2010, 07:13 PM   #14
Site Sponsor
 
ShootingSight's Avatar
 
Join Date: Jul 2004
Location: Cincinnati, OH
Posts: 2,685
Oops, just noticed Hawk pulled my 'shameless plug' post, based of not allowing selling/advertising in this area.

Sorry Hawk, the shameless plug comment was meant in humor. I thought an indication that reapir kits exist was germaine to the discussion at hand.

Art

ShootingSight is online now  
Old January 3rd, 2010, 07:47 PM   #15
MGySgt USMC (ret)
 
Gus Fisher's Avatar
 
Join Date: Nov 2008
Location: Virginia
Posts: 7,066

Awards Showcase

Quote:
Originally Posted by hueygunner View Post
gus:
those pliers are an esstential item for most aircraft mechanics.
they are for cannon plugs found on airframes engines and avionics and instruments.
technical name as per aviation types as well as dod types are pliers soft jaw cannon plug.
you can get them cheaper on ebay or right from any aircraft tool supplier.
gus you are a most knowledgeable guy and your posts are spot on. regards jeff shapiro hueygunner
Jeff,

That's great info and should be of good use to many folks. Thank you.

Gus Fisher is offline  
Reply

  M14 Forum > Gun Professionals > Gus Fisher


Search tags for this page
how to take apart a wwii garand rear sight
,
m1 garand rear sight assembly
,
m14 rear sight
,

m14 rear sight assembly

,
m14 rear sight disassembly
,

m14 rear sight repair

,

rear sight

,
rear sight movement
,
repair m 14 rear site
,
repairing rear sights on m1a
,
tight rear sight adjustment
,
working on rear sight assemblies
Click on a term to search for related topics.

Moderator Tools
Display Modes


Similar M14 Forum Discussions
Thread Thread Starter Forum Replies Last Post
NM Sights and what's different about them.. JunkyardDog The M14 46 April 26th, 2015 07:04 PM
Tutorial:GI Rear Sight (now SAI too) Assembly/Disassembly and Adjustment (pic heavy) tonyben Reference 21 December 16th, 2013 02:39 PM
any 444 Marlin shooters out there? Earthquake Lever Action 16 July 12th, 2013 03:15 PM
Rear NM Peep Sight Repair Question archmark Rifle Competition 6 December 1st, 2007 09:42 AM



Top Gun Sites Top Sites List