Have a question about the rear sight on my Colt 6920 M4 Carbine...
I've noticed that when I "bottom out" the elevation setting on my rear sight (set to "6/3" marking on flat), there is a little resistance in the last two or three "clicks."
The rear portion of the sight seems to be bottoming out on a slight angle when viewed from the side. Take a look at the photos - you'll see the gap that I'm talking about.
It seems as though the rear sight is catching on something when I adjust the elevation. I've owned a few of these carbines before and I don't recall ever seeing this issue.
Is this normal?
Red arrow points to the gap in question...
Pull the carry handle, and look at the bottom of the housing threaded section, and even the slot in that section for burs.
Either the bottom of the housing threaded section is bottoming out, or the slot in the threaded section has burs, and not allowing the housing to track the cross pin correctly, and all the way down.
Originally Posted By occasionalvisitor:
The rear sight is not suppose to be bottomed out.
The 6/3 marking is suppose to click on the last full click before the sight bottoms out, with a 1/4-1/2 click past the 6/3 position.
Set the elevation (sight in the rifle) using the front sight with the rear sight set at 6/3.
The adjustment knob can be adjusted to make the 6/3 land in the right position.
If you use RIBS or any of the revised zeros you should have several clicks below 6/3 that correspond to ranges of less than 300 meters.
OP you can add a couple of clicks if you follow the Revised Improved Battlesight Zero in the link below. When you're shooting at a known distance range you'll be able to dial your point of aim/point of impact in by adjusting the click wheel AFTER its sighted in with the front sight post. Unfortunately there are no markings for 100 and 50 meters but by counting the clicks below 6/3 you'll be able to dial it in. Its not as precise as scope turrets but you should be within an inch rather than inches
with the 6/3 setting for your do-all setting.
As for the sight not bottoming out, you're right something doesn't look quite right. You could loosen the index wheel screw and fiddle with the wheels separately to see if it will loosen up. Or ask Colt for a replacement.
Thanks for the input - that makes a lot of sense and adds some ideas that I wasn't aware of.
Fortunately, I've just purchased a new 6920 carry handle from a forum member here. That should solve the issue for me while I fiddle around with this one.