My rear sight is an A2 type sight (obviously).


I noticed that it doesn't touch or press up against the upper reciever on the carry handle on both sides. It presses up against one side. On the other side, there is a very thin gap. It is slight, but there. If I grab the sight and move it side to side, I can get it to wiggle just a hair so that the sight touches the carry handle on both ends. When I let go, it goes back to resting on one side (the side it always does) It seems as if there is some spring tension on it or something.


Is this normal? The sight doesn't wobble or move. It is still, but if I push on it, it will have, like I said, very slight rotational play.


I am wondering if this is a common thing. I am wondering if this adversely affects accurcy? I am just nitpicking here?


Here are pics of the rear sight. The arrow is pointing to the area where the very thin gap appears.

http://ranger.zftp.com/KP/ar15dotcom/rearsight3.jpg

http://ranger.zftp.com/KP/ar15dotcom/rearsight.jpg

Well, I cant comment on if it is supposed to be normal, but I wouldnt say that it is abnormal either. As long as the sight springs back into its original position when moved then you should be ok. I have 2 rifles with A2 sights and they both do this and it hasnt effected my accuracy at all.

yes its normal.... every A2 type sight does that.

It is by design. Only some match or ODCMP/DCM shooters get them pinned in place onto the upper receiver. It is spring loaded, that's why it does that. read on...


TECHNICAL NOTE 18: M16A2 REAR SIGHTS
BACKGROUND: Customer calls have disclosed considerable confusion over the construction of the M16A2 type sight used on ArmaLite® AR-10B™ and M15™ series rifles.

--------------------------------------------------------------------------------

FACTS:

1. The rear sight of M16A2 rifles is spring loaded in such a manner that it tends to rotate counterclockwise, as viewed from above. This biasing is caused by a ball and plunger in the left wall of the sight base, which presses against a surface of the receiver and forces the base to rotate. This is a means of taking up accumulated slack in the parts of the sight. The spring loading insures that the sight is always in the same position, even if cocked somewhat to the side. Keeping the sights consistently in the same position aids accuracy.

2. Depending on the buildup of tolerances, the cocking of the rear sight may be quite noticeable. While this may be somewhat unattractive, it is intentional, and is supportive of good accuracy. All M16A2 pattern sights display this cocking to some degree.
source: Armalite Tech Notes

It's normal. every single A2 rearsight I've seen does it.

Thank you so much!!!! You guys are the best.


I did some searching on it, but couldn't come up with that info.


Thanks again.

Just found this thread as i was about to post the same question.  Got my first upper today and this was the first thing i noticed.

Thanks for the info

Ummm... so whats the problem...it sounds fine to me

+1  That one looks fine!  Now go out and shoot it!  

I was worried about that too when I bough my first AR...it though I got taken, and would have to buy a new rear sight assembly.  ARFCOM is an amazing resource!