AR Sponsor
Posted: 8/3/2009 6:10:57 PM EDT
|
I just bought an LMT BUIS used. I've never owned one, or anything similar, previously. When it arrived, I was disappointed, as it has quite a bit of what I perceive to be "slop" inherent. The part of the sight that holds the reticle... that can be moved up and down using the dial, has a perpetual counter-clockwise cant that cannot be corrected. It seems as if the spring mechanism (whatever it is) keeps pushing the housing counterclockwise such that it is not square with the larger (main) part of the housing that attaches to the rail. Further, you can grab that sucker and wiggle the snot out of it, though you can feel spring tension, and it always returns to the canted position pictured below.
Am I just being picky? I have no experience with this type of BUIS to tell whether this is a normal amount of play or slop. After all... the reticle is generally in the proper location, and there's something to be said to having a tad bit of slop to allow for functionality in sandy conditions, etc. Nonetheless... it just seems like a "well machined" part shouldn't be so sloppy overall. You look at this sight, and it just looks like crap. The reticle housing is not remotely square to the main housing. Anyway... just looking for some guidance. Is this normal, or did I buy a lemon? The first three pics try to show the "slop"... (which, again, does not seem correctable). http://i167.photobucket.com/albums/u154/mroule/LMTS3.jpg http://i167.photobucket.com/albums/u154/mroule/LMTS1.jpg http://i167.photobucket.com/albums/u154/mroule/LMTS2.jpg This last pic shows the sight with the elevation all the way down, so that the threaded post is pulling the reticle housing down such that it contacts the main sight housing... and there's enough friction to keep it generally in line. In this position, the reticle housing is so low that it is below the markings/settings on the dial and contacting the main housing, which it isn't supposed to do. In short... it isn't usable in this position... it just looks square, as I imagine it always should? Or am I wrong? http://i167.photobucket.com/albums/u154/mroule/LMTS4.jpg So, let me know if this sight appears to be defective... such that I should see if I can do something about it with LMT, or whether I'm just overly picky and/or screwed having purchased a bad sight. Thanks in advance. |
|
The cant is perfectly normal with the LMT or any other A2 type rear sight. It is caused by spring tension, and a lack of tension will result in a sight that flops loosely around and is defective.
In other words that is perfectly normal. I think there is a sticky on this topic in the Troubleshooting Forum. Bottom the sight out at 6/3, zero for 50 or 100 yards (your preference/METT-T depending) and enjoy your new sight. Rob |
| If it bothers you take the sight apart, drill the proper size and depth hole on the right side, insert a spring and another detent ball on that side and reassemble the sight. Having a spring and detent ball on both sides will put equal pressure on both sides and keep it straight. |
|
The cant that you shown are normal and are a design feature which are common to all A2 type rear sights.
My LMT BUIS, Colt detachable carry handle and former fixed A2 rifles and carbine uppers are all the same, since my first fixed A2 rear sight on my Colt Sporter H-BAR rifle I bought in 1986. Take a look at the pics of the A2 sight this thread which also shows the cant, and also it have the instructions on how to adjust your sight and zero your firearm. RIBZ – – Revised Improved Battlesight Zero - thread link |
AR Sponsor