Hi,

I was following the information for 200 yd zero in Scott Duff's book, and noticed that it seems that I can't get the rear sight elevation wheel screw to tighten up fully (actually, the screw does tighten, but the sight will move some with recoil).

Is this problem something I can fix, or do I need to send it off to Fulton Armory or some other place?

Thanks,

-Zmeja

Maybe try some plumbers tape on the threads, or BLUE loctite.  HTH

Do you mean that the screw in the center of the elevation knob is tight AND that during firing, the rear sight drops one or more clicks? If so, tighten the screw in the center of the windage knob until you can not raise the elevation with that knob. Then back off a click or two on the windage knob screw. If that doesn't do it, check the serrations on the receiver elevation star. Possibly they are worn out in the area being used. No problem, loosen the screw in the center of the elevation knob and rotate the knob to a "cleaner" part of the serrations. This adjustment is used to adjust the range numbers on the knob to match the elevation applied. Nice for a fast set but not needed. Know your elevation clicks and apply appropriately (you can't read the little numbers in bad light anyway).

I guess what is confusing me is looking at the exploded drawings of the M14 rear sight group and then looking at my M1A (Standard, purchased new in December).

The book said to loosen the screw on the elevation knob side enough so the wheel settings could be indexed with the 200 yrd zero.  The screw itself is only about a 1/4 to 3/8 in long, and I couldn't loosen it enough without the sight moving on me.  I ended up (inadvertently) removing the screw (where I found out how long it is...from the diagrams it looks like it should go all the way through).  When the sight and wheel were set, I found that there is some rubber washer/sleeve inside the elevation wheel which prevents the short screw from being tightened easily.  I feel that it tightened back into its hole enough, but the elevation wheel seems to move very easily, and will move during recoil (lowering the sight).

The book made it sound like this was an easy task, and while monkeying around with this screw (and tightening it) shouldn't cause the sight to move around on you.  To tighten everything, I had to have the elevation wheel held in place, as well as the sight apeture.

-Zmeja

The screw on the left (viewed from rear),the elevation knob, only releases tension so that the elevation knob can be slipped and placed at whatever reference number you want. The problem with this practice is that you will always be using the same part of the serrations  on the receiver and wearing them down. Yes, the receiver is surface hardened; however, wear still does occur. As I mentioned before, to prevent the sight from dropping during firing, the screw on the RIGHT must be tightened. The M-1 and M-14 Rifles both use the exact same rear sight. One exception is that later elevation knobs are in meters and the older ones are in yards. For practical purposes this makes little difference. In the '70s I saw a 60 year old 300 yard firing line at a military post at was freshly marked "300 Meters". The firing line hadn't been moved, only the sign changed. Come to think of it, that was the same range that had a 55 gallon drum of water w/bucket for fighting small fires. It was painted red and marked "Non-PORTABLE WATER".

Ahh, so everything is clear now.  I'll need to reread the text in the book, but I didn't remember it saying anything about tightening the screw on the right.

When I get home tonight, I'll give it a shot, and then (hopefully) everything will be fine.

Thanks,

-Zmeja

Other than shooting the weapon, the standard way to check the rear sight elevation tension is to push down in the direction of the sight ramp travel. If too loose, the ramp will be pushed down and the RIGHT screw has to be tightened.

ArmyOrdGuy,

Thanks for your help.  Sure as anything, when I tried your test of pushing down on the apeture, it went down.  I tightened the right screw, and it's nice and solid again.

To be safe, I'll reconfirm my 100 YD zero tomorrow.

-Zmeja

Glad everything worked out well. Fulton would have been happy to charge you big bucks for the same thing. The only other suggestion I would make is to keep watch on the condition of the serrations on the left side of the receiver. If they start to look worn, loosen the left screw and rotate the elevation knob to a fresh unused part of the circle. Indexing the elevation knob to the yardage to be used is very overrated. Most serious shooters find how many clicks of elevation are needed and then click that on.

I took it to the range today to confirm my zero and sure enough, everything worked out fine.  The sights are still nice and solid.

Thanks again,

-Zmeja