New Colt SP6920 and rear sight slop
Curiousity finally got to me, and I decided to pick up an AR-15. Went with a SP6920 that a local gun shop had new-in-the-box. Being more of a "traditionalist", I want to become proficient with the iron sights on it as-is before I think about any optics. During my initial sight-in, I noticed the rear sight has some spacing between it and the carry handle infront of it, allowing you to twist the sight assembly counter-clockwise and clockwise. By default it wants to sit a bit counter-clockwise when elevation is turned all the way down. This means that the long-range apeture isn't perfectly straight for viewing.
Anyone know if this is "normal"? I don't think it is, but I can't prove it. I went back to the gun store at lunch (without the gun since its a work day and we can't have weapons on company property) to see if the others they had on hand were the same, but they had since run out of stock (my luck). A call to Colt results in a 30 minute wait to only be told "send the part in with a letter of the problem, and we'll see if its a problem". No option to exchange the sight or carry handle.
For now, I've put a bit of tape in the gap on the right side to take out of the spacing and straighten it out some. Of course I could just go out and buy a new unit or an aftermarket sight, but I just paid for these; I'd like them to at least "correctly" work first, and confirm it is unusual before I ship the carry handle assembly back to them. :)
It's normal, there is a mod that the CMP shooters do sometimes, it pins it so it can't swivel like that.
Pull the tape, you want the slight rotation/cant of the assembly to the upper receiver.
Look at the below photo, and note how there is a detent and ball on only one side of the assembly so it both tracks the single side of the receiver ear, and allows the hood to take a impact and still track true as well.
Yes, CMP rigs with small hooded apertures are mod'd so the assembly tracks on two front/back rods,more rigidly, but with these mods, any hit/hard impact to the assembly will end up with hood tracking/binding problems. If you are looking to have the rear sight NM mod'd,Compass lake is one of the builders/suppliers that can do this work.
I really appreciate the quick feedback guys. The use of phrases like "CMP", "NM", and "cant" (why didn't I think of that one?) also allowed me to find a lot more useful information that my google-fu wasn't turning up before. I am slightly less n00bish with black rifles.
Being a perfectionist, it bugs me, but hopefully it will grow on me. Otherwise, I'll find myself a NM rear sight.
Keep in mind that the NM hood mod to convert the sight assembly from ball detent to dual rod tracking is not a drop in part,but machining of the existing parts instead.
From there, you have a choice of aperture hooded opening size, front post width (both these a personal preference thing with how your eyes focus and how much of the target dot you want to outer ring exposes, front post width against the target dot), and then what adjustments MOA fractional clicks you want on the knobs for adjustments.
Bottom line, 600yards is not hard to hold in the X rings, but before you go full out for this in sights, might need to update a few more parts on the rig to get it to hold MOA or better first, before you go buck wild on a sight system that will be accurate that the rife it's on (see this often with over power scopes on hunting rifles, where the rifle will not group even close to the cross hairs on hold).