[acder]

Took my new to me Fed Ord rifle to the range today for the first time. Everything worked fine except the elevation wheel jumped settings after each shot, which is not conducive to a getting a good zero. After I figured out what was going on and reset the elevation after each shot the rifle grouped very well indeed. Where do I begin addressing the loose elevation wheel?

Thanks!

 

[liftrat22]

acder, several things to check. This is assuming that you have the later (T105E) type sight, and not a lockbar. Check the tightness of the slotted nut at the center of the windage knob. This nut pulls the elev. pinion against the left receiver ear. It should be tight enough to hold the elev. setting, but not so tight that it makes changing windage difficult.
Also, check the tightness of the screw at the center of the elevation drum. If this screw is loose, the drum (the part with the markings) can rotate on the pinion. There is also the possibility that the nub on the elev. drum is worn down, or that the serrations on the receiver with which it mates are worn. That should be a good start. let us know how it goes.

 

[30Caliber]

The M14 field manual FM23-8 covers this in, I think, section 28, Regular Maintenance under the heading of things you should do prior to firing.

 

[Gus Fisher]

When I check M1 or M14 adjustable rear sights and no matter if they are NM or standard, there are a few tools I grab real quick.

The first is a pair of what Brownell's calls "Magazine Tube/Cap Pliers." They jaws are tough but soft so there is no damage when grabbing hold of the elevation pinion drum so you can tighten the screw. I've heard these same pliers are used in the automotive trade and if so, they would be cheaper to buy at an auto parts store. Maybe someone from that trade will recognize these pliers and let us know what they are called in the automobile trade.

http://www.brownells.com/aspx/NS/store/productdetail.aspx?p=13787&st=&s=

The next things I grab are two Brownell's Magna tip bits. I found these two sizes fit virtually every G.I. pinion and windage knob:

080-360-650
Bit #360-6, SD=.360, BT=.050 $2.92

080-240-750
Bit #240-7, SD=.240, BT=.050 * $2.92

You can find them listed on this web page:

http://www.brownells.com/aspx/ns/store/ProductDetail.aspx?p=417&title=MAGNA-TIP SUPER SETS?

You also have to have one bit driver handle and you could get that from Brownell's but they are also available at most hardware stores.

OK, so you grab the elevation pinion drum with the Magazine Tube Pliers and use the larger 360-6 bit to tighten the elevation pinion screw. Once tightened, you are done with that bit.

Then check to see if you have good audible clicks as you turn the elevation pinion up and down. If not, the pinion may not be tight enough. Then you use the smaller 240-7 bit to tighten the nut in the windage knob until it just "jumps" into place the first time. I've found this is almost the ideal position for most rear sights. Occasionally you have to tighten the windage nut one more "jump" if the sight is not tight enough with a elevation pinion that has a worn internal spring.

Now if you have good audible and repeatable clicks of elevation, try turning the windage knob. If you can turn it without wearing out your fingers that's good. Turn it right 8 clicks and back left 8 clicks to ensure the rear sight base moves according to the scale on the receiver. Then turn it left 8 and clicks and back to the right 8 clicks to see it does the same on both sides of the windage scale on the receiver. If that works properly, you are done with this step. If it is so tight you can't turn the windage knob, then you either turned the WK nut too far or the elevation pinion may be worn or you may need a RS cover (spring) that is tighter. You may also have to do some work on the bottom front of the aperture slide.

I think I should write an additional post on what to do next if the RS doesn't work, but that is going to be a long post and will have to write it later.

 

[tonyben]

Those would be called Cannon Plug Pliers or electrical connector padded pliers....

Here's a set for half the price:
http://www.spenroaircrafttool.com/cannon-connector-pliers-h116-p-156.html
http://cgi.ebay.com/ebaymotors/Cann...012QQitemZ220397567699QQrdZ1QQsspagenameZWDVW

Every avionics tool box has one. GI7

 

[Gus Fisher]

Those would be called Cannon Plug Pliers or electrical connector padded pliers....

Here's a set for half the price:
http://www.spenroaircrafttool.com/cannon-connector-pliers-h116-p-156.html
http://cgi.ebay.com/ebaymotors/Cann...012QQitemZ220397567699QQrdZ1QQsspagenameZWDVW

Every avionics tool box has one. GI7

Great info Tony. Isn't hard to tell I spent all my time in the Corps on the Ground side, eh? Grin.

 

[acder]

First-thanks to everyone who took the time to answer my question.

After following your advice I ended up tightening the windage screw "one click". That seems to have tightened the elevation drum substantially but I can still turn it by hand. So I think I am good now but will find out for sure when I hit the range this weekend.

Thanks again. It is a wonderful thing when experts in a field take the time to answer what was probably a pretty basic question and help out a neophyte.

 

[Gus Fisher]

First-thanks to everyone who took the time to answer my question.

After following your advice I ended up tightening the windage screw "one click". That seems to have tightened the elevation drum substantially but I can still turn it by hand. So I think I am good now but will find out for sure when I hit the range this weekend.

Thanks again. It is a wonderful thing when experts in a field take the time to answer what was probably a pretty basic question and help out a neophyte.

Here's a little tip in case you find it hard to move the windage knob. Push in on the head of the screw in the elevation pinion while you move the windage knob. That takes tension off the knob and makes it a lot easier to move. This is something I show folks when their pinion has a worn spring, but you can still get a lot of use out of it by using this technique.