What are the pro's and cons of the solid (non flip) rear site, and the flip up/down rear site systems?

One personal question I had was, with the rear flip up/down site would it be possible after time to be off zero? What I mean is most spring loaded devices tend to wear after time and be able to be push more to the front or back instead of a 100% center position. I do not own one at this time but I need one, so maybe we can have the owners of these items to speak there peace on there flip or solid buis/rear site






pix borrowed from http://www.rainierarms.com/

Try using the search feature.

While I have no extensive knowledge of the many manufacturers of these sights, I do use the flip up (from GG&G) rear BUIS.  IMHO, I would probably have finger failure before I could inflict enough wear and tear on the sights to affect POA/POI.  From what I have read on this forum, the flip up BUIS are very usefull to have available in the event ones primary sight device (Aimpoint, EOTech, ACOG, scope, etc.) goes Tango Uniform.  I have a flip up rear BUIS as I am not an operator and have the leisure time to swap around primary sight devices at the range just because I can.  With the flip up BUIS, I can try out my my cowitness with the AimPoint, take off the AimPoint and use the BUIS (I have a fixed front), or fold my rear BUIS and slap on my tactical scope.  

With a fixed BUIS, I would have to reorganize my scope or get higher rings things like that.  Excuses, excuses. Just my $.02!

A quality folding BUIS will not wear out like you describe.

Fixed rear sights will ALWAYS be there when you need them, but they can interfere with sight picture, especially in the case of shooters who attempt to line up the sights AND an optic reticle.

Flip sights are lighter, and conveniently out of the way till you need them. Or, circumstances depending, it will STILL be folded when you need it.

I personally believe that the durability advantage of the LMT buis is offset by the possibility that you will rotate the knobs accidentally. I like the Troy flip sight and the LaRue fixed sight.

Fixed = Some are adjustable for elevation.  Always ready.  Nothing to deploy when Murphy visits.  Some say they obscure your view downrange (albeit by a tiny margin).

Folding = Typically not adjustable for elevation.  Can be folded down as to not obscure your view.

 To me they have different uses.  I use fixed for my CQB and blaster rifles.  And I use flip-ups for my long range rigs, so they are not in the way of my optics...  Pick a quality one that suites your use/needs.

Weazer  

Quoted: Try using the search feature.

I DID!
img.photobucket.com/albums/v225/ogcujo/Posting/0545.jpg


I just ordered my rear site right before I checked up on the thread. I got The GG&G A2 Style BUIS (Back Up Iron Sight). I feel more comfortable with the detent vs the spring.

Quoted: A quality folding BUIS will not wear out like you describe.

Stick I know the quality of these things surpass any doohickey spring but you can  NEVER underestimate Murphy's law.

I have a Troy that I am pleased with.  It does not use a spring and it folds down low enough to mount a scope.  The LMT buis is hard to beat for CQC.

Keep your eyes on (pun intended ) that GG&G unit.  The model I examined had quite a bit of play in it when deployed.

Quoted: Fixed = Some are adjustable for elevation.  Always ready.  Nothing to deploy when Murphy visits.  Some say they obscure your view downrange (albeit by a tiny margin). Folding = Typically not adjustable for elevation.  Can be folded down as to not obscure your view.

Elevation adjustments aren't a good thing on BUISs though. And, using the KISS paradigm, if it's not good, it's probably bad....

Quoted: I just ordered my rear site right before I checked up on the thread. I got The GG&G A2 Style BUIS (Back Up Iron Sight). I feel more comfortable with the detent vs the spring. img.photobucket.com/albums/v225/ogcujo/Posting/A2StyleBUIS_320x169.jpg Quoted: A quality folding BUIS will not wear out like you describe. Stick I know the quality of these things surpass any doohickey spring but you can  NEVER underestimate Murphy's law.

If I would have known you were going with that one, I would have phrased my comments different.  

Its not for MIL/ LEO use is it?

Originally Posted BySeth_Livzz Keep your eyes on (pun intended ) that GG&G unit. The model I examined had quite a bit of play in it when deployed.

Its a A2 unit (I don't have the model number)

Quoted: If I would have known you were going with that one, I would have phrased my comments different.   Its not for MIL/ LEO use is it?

No man, its for home defense, I plan to put a different site like a ACOG or Eotech, but I need a back up site till I can get the ACOG. Why? Is there something wrong with the GG&G? If so let us know. I need you to tell me whats the best to get, I want a ACOG on my flat top.

This is some stuff I posted on another board. I am hoping to get a little more play on here. I realize that the various BUIS have been discussed at length on this board prior to this, but I often don't read stuff only to become interested in the subject months later.

One thing to keep in mind when chosing between fixed or folding BUIS is, what are you using for a primary sight ? For instance, an ACOG not only needs a folding sight, it also needs a very low profile folding sight.

This past weekend I took the Frontsight Practical Rifle, Two day skill builder. I have taken this class twice before: once with an Aimpoint ML2 and once with a TA31F ACOG. This time, I took the class using only my Troy duel aperature BUIS.
This was two days, somewhere around 700 rounds, 7-200 yards, with VERY tight time constraints. Times range from 1.5 second head shots at 15 yards out to 6.5 second COM shots at 200 yards.
Bottom line: I did horrible. By FAR the worst I have ever done in any class or competitive venue.
I used the large aperature all the time. This was the advice of the instructor. I did fire a couple groups with each aperature and it seemed like they both were not on the same plane. This could have just been how bad I was shooting, but at this point, I don't know. If they were both on the same plane, I think I would have done better with the smaller aperature, but I don't know since I didn't try it.
I think that one of my major problems was that I wasn't getting a consistant cheek weld. I blame this on my use of optics for years. With a dot optic, cheek weld doesn't matter. With iron sights it is critical. I think that if I took the same class again, starting tomorrow, I would do OK. But, this kind of shooting with iron sights takes some serious training: and I don't have it.
I do have a couple negative comments about the Troy sight. One thing about the Troy BUIS that I consider a huge disadvantage is that I was unable to adjust the windage on mine with a bullet (I knew this before the class). I used a pen both times I adjusted mine. This is unacceptable to me. The sights should adjust with whatever you have on your person when you are firing the rifle: not a special tool. This usually means a bullet. The second thing is that ONCE during this class I looked down at my weapon and found that the rear sight aperature had rotated to half way between the large and small aperature.
If you were in combat or whatever, this would be a bad situation: you would have no rear sight.
So, there is more to the discussion besides whether or not the BUIS locks when open or it locks when closed. We also need to know about the aperature. After this experience, I would have to say that I think having a single aperature would be better. First of all, it can't rotate like mine did. Second, why do we need two aperatures anyway ? I suppose if you bought a flat top and didn't have the money for an optic and were using this sight as your only sighting system, having two aperatures makes sense. But as a BUIS, I would think that having only the large aperature makes more sense. If you were going to use the sight a lot: more than just a back up, I can see where having two, same plane aperatures would be a plus. But, not if it is possible for the aperatures to rotate so that you can't see through either one.
On the standard carry handle M16/AR15 we have two aperatures: one is for zero to 200 and the other is for use beyond 200: on the A2 the small aperature is used with the range knob. So, if we only had the large aperature designed for use at 0-200 yards, I think we would be fine. Simple is better.

The guy shooting next to me had a GG&G MAD BUIS on his gun. I liked the look of it. I think I might give it a try.  It locks in the up and down positions as I understand it. It also has two aperatures, BUT the aperatures arn't on an "L" shaped piece of metal that flips one way or the other. The MAD aperatures are selected by rotating a "wheel" type thing. So, can this wheel get rotated so that it is inbetween aperatures ? Another plus with this MAD sight is that the two aperatures are on the same plane. So instead of one being the short range sight and the other being the long range sight: we can use either, at any range depending on lighting and on the need for speed. If we were shooting on a range at paper targets, we could use the small aperature for greater accuracy. If we had a 300 yard shot at an unsuspecting, stationary enemy with lots of time and a solid rest, we could dial up the small aperature for a precision shot. During a class such as the one I took this weekend, I could have tried the smaller aperature and if it didn't work out, I could have switched to the big one while maintaining my zero.

There is a sticky at the top of the first page concerning BUIS, but it just lists the various sights and their features. It don't really have much comment on the various sights.

Just my $.02, but most BUIS's are pretty close and will get the job done. you really need to pick if you like a fixed of folding. As to adjustment,, it's calld a BACK UP sight for a reason.  Why would you want it to be that adjustable. Once you have it zeroed for your specific range/need, it's done. Hell, I've had mine on for over 2 years and check it by doing a couple of drills with just the Iron's and it's always Minute of bad guy.

I like my BUIS like I like the spare tire of my truck. I don't want it on the hood where I have to look at it and over it all the time.....  I want it out of the way until I need it.  And that whole "but what if my sight goes down and I need a BUIS right Now" Hulabaloo... use your M2/EO and your front sight and pop um. anything outside of CQB range, you got the extra 1.5 seconds to pop up your BUIS... I hate shit in my feild of view..defeats the whole purpose of the reflex sight  and keeps you from inadvertently trying to line up the dot and your irons (cause I know some of you do...and won't admit it...)

"As to adjustment,, it's calld a BACK UP sight for a reason."

Yeah, it's a backup right up until the time you are using it: then it is your primary sighting system. If I can have one that is not a comprimise in any way, then that is what I want.
Sights need to be adjusted. On the AR15/M16 you can adjust your elevation by turning your front sight using the tip of a bullet. On the A1 configuration, you adjust your windage with the tip of a bullet. With the A2 rear sight, you twist a knob to adjust for windage.
On the Troy sight, the windage adjustment has a similar set up to the A1 rear sight, however, a bullet tip is too small to be inserted into the hole to adjust the sight. WHY ?
I don't care what sighting system I am using, I want a good solid zero and the ability to engage a target out to the effective range of the cartridge. If that sighting system is a BUIS, it doesn't matter. I have fired my rifle with BUIS extensively at 200 yards and am sure of my zero. I also made sight adjustments as my zero was refined. During that class I mentioned above, I used 55 grain bullets: they are cheap and perfectly suited to the purpose. In my more precision shooting at the range, I normally use 77 grain Sierra Matchkings. Guess what ? That requires a new zero: I have to adjust the sights. I also have a suppressor which shifts the point of impact about two minutes. This either requires Kentucky windage or .................. a sight adjustment.

Big Bad BUIS FAQ

Yeah, as I said in my first post: "There is a sticky at the top of the first page concerning BUIS, but it just lists the various sights and their features. It don't really have much comment on the various sights. "
Basically just a catalog.

I was undecided about fixed and folding rear BUIS because of the way a fixed one will obscure the target. But when I finally got to try it with an Aimpoint and a  Larue fixed rear BUIS, I found that I did not even notice the Larue when shooting with both eyes open. After all, I once had the old Occluded Eye Gunsight, where the sight IS TOTALLY OBSCURED on purpose in one eye. Your Brain is not confused, just the Intellect that says "I won't be able to see the sight because something is in the way".

That being said, I chose the Larue over the others because it is simpler, having just the A1 flip (but with an A2 aperture) system instead of the A2 controls like the LMT pictured at top. In this situation, for a general-purpose rifle, simplicity and toughness were what decided my choice.

For my RECCE I chose the KAC 600m folding rear BUIS (and a PRI folding front sight) because it is primarily an optics weapon and once zeroed I never plan to use the irons. I picked the KAC because it has BDC, more at place on a precision rifle than a general-purpose one.

Originally from 444

I don't care what sighting system I am using, I want a good solid zero and the ability to engage a target out to the effective range of the cartridge. If that sighting system is a BUIS, it doesn't matter. I have fired my rifle with BUIS extensively at 200 yards and am sure of my zero. I also made sight adjustments as my zero was refined. During that class I mentioned above, I used 55 grain bullets: they are cheap and perfectly suited to the purpose. In my more precision shooting at the range, I normally use 77 grain Sierra Matchkings. Guess what ? That requires a new zero: I have to adjust the sights. I also have a suppressor which shifts the point of impact about two minutes. This either requires Kentucky windage or .................. a sight adjustment.

Sounds like you like to adjust your sights....alot. you have a lot of different zeros for a lot of different stuff, different ammo, suppressors. The LMT Fixed Adjustable sight (pic shown at the top ) sounds right up your alley, then get a  replacment Sight Aperature that has both  Aperatures on the same plane (No difference in elev from small hole to large hole)  The Standard Aperature that comes with most irons is offset to allow for the trajectory difference at the different ranges out to 800Meters (max Effec for 20" M16 series rifles)

No special tools and you can putz with it to your hearts content

And the advice about using the large Aperature was not the best..I know the manual says to use the large Hole Aperature out to 200M but you get a tighter /less error induced sight picture using the Small Hole. The large hole is really only useful in low light. In all my years shooting Irons, I never used the large Hole Aperature....

Quoted: Quoted: Try using the search feature. I DID! img.photobucket.com/albums/v225/ogcujo/Posting/0545.jpg I just ordered my rear site right before I checked up on the thread. I got The GG&G A2 Style BUIS (Back Up Iron Sight). I feel more comfortable with the detent vs the spring. img.photobucket.com/albums/v225/ogcujo/Posting/A2StyleBUIS_320x169.jpg Quoted: A quality folding BUIS will not wear out like you describe. Stick I know the quality of these things surpass any doohickey spring but you can  NEVER underestimate Murphy's law.

you did not search hard enough

tacked thread in the optics forum about buis'

Quoted: What are the pro's and cons of the solid (non flip) rear site, and the flip up/down rear site systems?

Fixed:  usually pretty big.  Might be seen to take up a lot of space on the rail or above the rail or in the LOS of an M68 or similar.  But it's always there and doesn't have to be deployed.
Flip:  usually a lot smaller.  Kept out of the way until needed.  Quality models flip up with minimal effort, some with tension to keep them up when knocked around.  Some with similar adjustments available to teh A2 sight.  Some have annoying habit of deploying with the small ap as default.  Some are overly fiddly with lots of minute adjustments.

One personal question I had was, with the rear flip up/down site would it be possible after time to be off zero?

First of all, that's not an issue with a good sight.  Second, it's a BUIS.  A "backup" by definition.  Meaning not primary.  It's there to get you by until you get your primary system back online in most cases.  Third, as a BUIS I don't know what level of accuracy you are wanting.  If you want NM results use a NM iron sight.