BUIS options

[CodeSeven]

A small dilemma here. I currently run an Aimpoint ML3 in a LaRue LT150 mount. I have a standard fixed FSB and a Troy folding BUIS. I'll be selling the rifle shortly and the Troy will need to go with it. I plan on my new upper having a fixed FSB and placing my Aimpoint setup on that. But...I'll need a new BUIS. I've considered buying another Troy folder or possibly going to a fixed BUIS. The two fixed I'm looking at are the DD A1.5 and the LaRue LT103 w/ the VFZ mount.

So, the first question is fixed or folding? Either fixed option would be cheaper than a new Troy. Are there any cons to the fixed setup?

Second, if I went fixed, which sight would be recommended? It appears both sights are similarly priced.

Thanks!

[Backstop]

On my 6721, I have an ML3 in a LT150, and have a Troy BUIS on it.

Back in Nov 2008, decided to try the LT103, so sold the Troy. Matter of fact sold it to a member here.

The LT103 is outstanding.

Problem was, having that rear aperture so close to my eye, I kept dropping down and using the irons. I just couldn't stop doing it.

So I sold it, and bought another Troy.

Yeah, I failed to properly train-into the LaRue fixed BUIS.

I can live with that.

But if I ever again have the need for a fixed BUIS, the LaRue is the only one I'd buy.

[Boss302]

My current rifle wears MBUS front and rear. Granted I do really like them and have had no issues, I do believe my next build will have a set of fixed irons. Probably DD on both ends, which is kind of a given considering I've amassed quite a few DD parts for my next rifle.

[Pax]

Proponents of fixed irons will tell you that in moments of stress you will or at least ought to have trained to focus on the few points of focus that matter, namely the target and your optic's dot. They will also say that fixed irons are simpler and therefore more reliable systems. This cannot be denied, but it certainly does not mean that your Troy folders are going to fall apart any time soon.

The only gripe I've heard from advocates of folders is that with fixed irons you involve so many points of focus in your sight picture that it becomes too obscured to be practically usable. Not only have you got your target, FSB, reticle and rear aperture but then youve got bunny ears and the optic housing itself to consider and it all just makes for one hell of a messy sight picture by comparison.

I say experiment with both if possible to determine which is or is not for you. A reasonable way to do this would be to buy a new Troy rear BUIS and try running it deployed at all times. See what you think. Better yet, give it a try while youve still got this rifle and see if it's workable.

[Magic_Salad0892]

Fixed BUIS 0-300m: Daniel Defence front, and rear fixed sights.
Fixed BUIS 0-600m: LMT front, and rear fixed sights.
Folding BUIS 0-300m: KAC 300m micro rear, KAC M4 flip up front, or KAC micro front BUIS.
Folding BUIS 0-600m: KAC 600m micro rear, KAC M4 flip up front, or KAC micro front BUIS.

Hope that answers it.

[Crow Hunter]

I tried both when I got started.

I wound up standardizing on folding.

My reasoning:

I have a magnifier that I switch between rifles.

I also may in the future find that "perfect" do all optic that most likely will not fit in front of a fixed rear sight and having a folding rear sight makes it easy to switch between magnified and non magnified optics.

I when shooting from prone at an elevated target, my view of the target/dot could get partially occluded by the rear sight ears/base if I got too low on the stock. (This is with a lower 1/3 mount)

My experience was with a Larue fixed rear sight, UTG copy of the LMT (on a M&P 22) and Troy, MI and MBUS rears.

-The Larue was solid as a rock, very clean sight picture.
-The UTG is well, UTG. I prefered the Larue sight picture.
-The Troys feel very nice, not something that I would want to run as a primary sight up all the time though. Nice clean lines, folds out of the way completely.
-The MBUS felt cheap, and the sight picture felt even more cramped than the UTG. It was on a friends gun (S&W M&P MOE) that I help sight in so my experience is very limited with them. He loves it however and is an excellent shot with it.
-The MI rear sight was on my brothers DPMS .308 (I forget the model). They were okay. I didn't like them as good as the Troy's but better than the MBUS.


Personally, I prefer the Troy of the ones that I have experience with.

[Failure2Stop]

I only started using folding rear sights when I started using a magnifier with my RDSs and low-powered variables became viable.
Magnifier on, rear sight folded down.
Magnifier off, rear immediately goes up and stays up.
Variable goes on, sight folds down.
Variable breaks, variable gets dumped and irons go up.

I haven't used every BUIS out there, and I am a product of my training so I have developed preferences, but the following are my favorite;

Fixed Rear: LMT (or cut down "carry handle")
Folding Rear: Troy

[Doc Safari]

I'm in my infancy as far as the learning curve on BUIS options, but here are some observations:

Folding sights have more moving parts and Murphy's Law says that the folding mechanism is what will fail when you need it. Currently I would use a folding BUIS if I were to mount a scope that might need to overhang where the rear sight is mounted.

I like the Daniel Defense fixed BUIS, but I've read that the apertures are not in the same plane. I've not tested the way this changes the zero between apertures, but you know it has to.

The PRI folding sight seems fairly robust, but the apertures depend on a spring and detent ball to stay in place, as opposed to the flat spring on the DD unit. The former seems a little Mickey Mouse for a "combat" sight, but I could be wrong.

I'm becoming more a fan of the chopped carry handle. One, if you buy a milspec carry handle you know it's quality. Two, I've read that LMT may be cutting corners on its BUIS, so chopping a carry handle may be better quality than the LMT unit, which I guess uses cast (?) body components now.

I don't trust plastic BUIS sights, but that's just because I'm old school.

Somebody feel free to correct me if I've related any of the above incorrectly.

[Dutchy556]

Personally I like a fixed rear with a red dot unless one of the following is true:

-You run, or may in the future run, a magnifier or nods behind your rds
-You may at some point want to switch to magnified optics

I like that a fixed rear is always right there, if your dot goes down you just switch to the irons, no flipping anything up. That said you could always just run a flip up in the up position as has been mentioned, though theoretically a flip up does have more potential for failure. Quality sights like the Troys have proven themselves to be quite durable however.

Some don't like the busy sight picture of a fixed/deployed rear. I don't even notice when running a lower 1/3 cowitness but to each his own.

Really the main advantages in my view of a fixed rear would be cost vs. something like the troy, and in theory simplicity/reliability. My preference, having used the LaRue, LMT & DD is the DD 1.5 - light, slick, simple and inexpensive. For a folder - Troy hands down.

If I were you CodeSeven, assuming you're running just an RDS with nothing to mount over the buis and not wanting to switch to magnified optics, I would try the fixed option and see if it works for you. If it does you've saved a little money over a Troy. If you dislike it, you should be able to turn around and sell the like-new fixed on the EE without much issue. Just a thought...

[lethal dose]

I like folding rear for absolute cowit and fixed rear for lower 1/3 cowit. I almost always prefer a fixed front.

[CodeSeven]

Thank you all for the info. I'm leaning toward the fixed option as this point. I only plan on running my Aimpoint with irons in the lower 1/3. I don't intend to add a magnifier or anything else. I flipped up my current Troy and ran with it for a while and didn't have an issue with it being up. However, after reading these replies, I'll be sure to check it out in the prone.

Dutchy556, money aside, what are the differences between the DD 1.5 and the LaRue?

ETA: Also, is a same plane aperture worth the extra coin?

[kaltesherz]

I have both LMT and LaRue fixed rear BUIS and think they're the shiz-nit. LMT works better if you want a more versatile rear but aren't planning on removing it, LaRue works better if you want something simpler and might be taking it on and off and want to keep your zero. I currently run the LaRue so I can take off my M3 and throw on a TA11. Works awesome.

[Cagemonkey]

For a fixed rear adjustable sight, I like the LMT. For a fixed rear non-adjustable either the Daniel Defense or Larue. The Troy is pretty much the gold standard in a folding rear sight, though the new Diamondhead looks really nice.