News:

Want Appleseed to grow and fill our firing lines?  We need help with advertising, social media, graphics design, and administrative tasks.  An hour of time spent at this level can have a huge impact.  You can make a difference!  Send a Personal Message to Cleveland.

Main Menu

Springfield M1A Rear Sight Problem

Started by theri, February 17, 2011, 11:09:41 PM

Previous topic - Next topic
Print
Go Down Pages1
User actions

theri

February 17, 2011, 11:09:41 PM
I have a Springfield M1A Loaded model rifle and I replaced the rear sight aperture with a National Match "hooded" aperture.  I was able to sight this rifle in at 25/200 yards but it required that the rear sight be "cranked all the way down" to the lowest level. 

I have thought that maybe I need to grind off some of the teeth from the bottom of the rear sight aperture so that will might be able to move lower in the sight base but I am not sure that this will solve my problem. 
Does anyone have any comments or suggestions as to what the problem might be before I take the rear sight apart and have to re-zero my sights again especially if this does not solve the problem?

Thank you for any assistance that you can provide.

Terry
Whiskey Tango 9

Pvt.Joker

#1
February 17, 2011, 11:51:57 PM
First, not sure I see the problem...if it's got a good zero, great.
I wouldn't fool with the rear assy. If you must have some space under the rear sight, do it by putting a taller front sight on the rifle. This will have the effect  of lowering the point of impact, and requiring more clicks up on the rear to hit the same zero.
BTW, the opposite modification is more common. If you are shooting iron sights out at 1000 yards, it comes to something like 40 clicks....makes the cheek weld durned difficult. The fix is to cut the front sight down...

HTH!
"The battlefields of history are littered with the bones of those, who, at the dawn of victory, sat down to rest; and, resting, died."   
"We can't guarantee success in this war, but we can do something better. We can deserve it."
-John Adams, in a letter to his wife, Abigail.

Camljr

#2
February 18, 2011, 01:49:08 AM
Actually, the rear sight base that is used for the hooded aperture IS cut lower to make room for the aperture.

It was designed to be used with the NM sight base, which is 1/2 MOA per click, and a fine thread (64 TPI) windage knob.

It CAN be used with the normal base, but will not go as low as needed, unless modified...

You CAN grind the base of the hooded aperture at an angle past the first tooth, and it will give you some ability to lower the elevation.

Also, if you grind the base of the aperture, you can also change it out without disassembly...

Just crank it out, and crank the regular one back in. Of couse, the regular aperture must be modified also...

96 SHOOTS SO FAR!

WSMR Instructor 03/10  -  SAPPER STEEL!

�The real man smiles in trouble, gathers strength from distress, and grows brave by reflection�   Thomas Paine

Proverbs 22:3  -  A prudent person foresees danger and takes precautions. The simpleton goes blindly on and suffers the consequences.

"Far better is it to dare mighty things, to win glorious triumphs, even when checkered by failure... than to rank with those poor spirits who neither enjoy, nor suffer much, because they live in a gray twilight that knows not victory or defeat".
Theodore Roosevelt

Old Dog

#3
February 18, 2011, 07:02:42 AM
When the aperature is all the way down does the hood contact the base?  Or does it bottom out/stop with a gap between the hood and the base?

Some folks disassemble the rear sight, remove the aperatue and grind off a portion of the bottom of the aperature.  Sometimes the tip of the bottom will contact the receiver and stop the aperature from moving downwards further.  I know I've seen pictures of what the aperature looks like after folks do this but so far I haven't found one.  Do a search on the web and you many find such a picture along with the description of how to do it.

My M1 NM rear aperature is completely bottomed out to allow me to hit point of aim at 25 meters.  I didn't see any need to be able to adjust it lower if it hits where I want it to hit. 
"The rifle itself has no moral stature, since it has no will of its own. Naturally, it may be used by evil men for evil purposes, but there are more good men than evil, and while the latter cannot be persuaded to the path of righteousness by propaganda, they can certainly be corrected by good men with rifles."

—Jeff Cooper, The Art of the Rifle

Colorado Pete

#4
February 18, 2011, 04:05:45 PM
If you are on at 25/200 you'll be about 1 3/4" to 2" high at 100. No real need to lower the rear sight any further if you know that.
"Good shooting is good execution of the fundamentals. Great shooting is great execution of the fundamentals. X's are what you want. Tens are okay, but nines indicate you've got a problem" - Jim Starr
"The purpose of shooting is hitting" - Jeff Cooper

dragonfly

#5
February 18, 2011, 08:36:15 PM
I assume you are using 6 0'clock hold.
If you have M1a loaded, it already has a NM rear sight base. Which means windage adjustments are 1/2 MOA and elevation is 1 MOA. When you install the hooded aperture you gain your 1/2 MOA adjustments by turning the hood 180 degrees. If the notch on the hood is pointing down, this will give another 1/2moa drop in POI if needed.
If the hood is already bottomed out you probably wont gain much by grinding any teeth off the aperture. You can grind that bottom tooth to a taper, and make sure you remove any burrs the teeth may have, but I would read about it first.
Other than that a taller front sight is the best fix.
A couple of books I would recommend are; The M14 Owner's Guide by Scott A. Duff and John M. Miller, and The M14 Assembly Guide by Walt Kuleck and Clint McKee.
Also  www.m14tfl.com  This a great resource and has alot of valuable info.

D-fly
www.facebook.com/WIAppleseed

K.I.S.S.
Lead, Follow or Get out of the way - Thomas Paine
Did you talk to someone new about APPLESEED today ?
The United States Constitution.

wcmartin1

#6
February 19, 2011, 07:04:32 PM
"Unhappy it is, though, to reflect that a brother's sword has been sheathed in a brother's breast and that the once-happy and peaceful plains of America are either to be drenched with blood or inhabited by a race of slaves.  Sad alternative!  But can a virtuous man hesitate in his choice?" - George Washington - from a letter to a close friend after the events of April 19, 1775

"There is no nation on earth powerful enough to accomplish our (the United States) overthrow.  Our destruction, should it come at all, will be from another quarter.  From the inattention of the people to the concerns of their government, from their carelessness and negligence, I must confess that I do apprehend some danger.  I fear that they may place too implicit a confidence in their public servants, and fail properly to scrutinize their conduct; that in this way they may be made the dupes of designing men, and become the instruments of their own undoing." - Daniel Webster, June 1, 1837

theri

#7
February 19, 2011, 11:57:21 PM

wcmartin1,   Thank you.  This is EXACTLY what I was looking for

Thank you to all my fellow Appleseeders that responded.

Terry
Whiskey Tango 9
Print
Go Up Pages1
User actions