Position of rear BUIS on your AR15 question

[Rockrivr1]

I've got a question about the position of the rear BUIS on my AR's rail. In the pic below, you'll notice that my Trijicon is right over my fold down BUIS. I have adjusted the position of the Trijicon so it's right up against my rear BUIS now.

While shooting in this configuration I'm losing a good amount of the peripheral view through the Trijicon. It's just a little to forward with the way I have my cheek weld on the stock. To compensate, I've moved my cheek forward on the stock, but it was just not comfortable. I removed the rear BUIS and slide the Trijicon (On it's new LaRue Quick Disconnet mount ) all the way back. In this position I now have an almost full view through the Trijicon and I'm able to shoot better with it now.

Here's my question though. I don't want to keep the BUIS off the rifle just in case of a problem with the Trijicon. So, I've mounted it in front of the Trijicon with the folded down sight pointing towards the bbl when folded. In a normal shooting day I can remove the Trijicon and I obviously have all the time in the world to move the sight back to the original position as needed.

If though I'm in a SHTF scenario (Not that I ever would be) and I just flipped up the BUIS in that position and use it, is there any reason I would not be able to accurately shoot that way? It seemed to be OK to aim in my basement, but haven't live fired it that way yet.

 

[MassMark]

I'd try firing it that way, but I'm not sure if it will work. Is that an ARMS?, (I can't remember). It looks like a great sight, but pretty thick - it's why I like the Troy BUIS, (which folds flat and offers more in the way of clearance. I'll bring my spare to the shoot and you can give it a whirl, (it looks as if my Anvil upper will not arrive by then anyway ). I'm not sure about your sight, but I think it's designed to be used at a specific sight plane. It may be doable by adjusting your front post, (if there's enough play).

 

[News Shooter]

At the risk of appearing any more ignorant than I actually am...


What is a BUIS?

 

[suicide 7]

Back up iron sight
just in case your "high speed" optics go south

 

[News Shooter]

Back up iron sight
just in case your "high speed" optics go south

Thanks

 

[Dench]

BUIS is a odd topic, and i think people dont look into the scope of the issue to well. if your in a situation were your optics have been damaged, it takes about 10 seconds total to take a ACOG off and put BUIS on correctly. thats not that bad, even if you were in the middle of the zombie invasion.

if the acog gets shot (from any angle), id be more worried about all the pieces of broken glass, metal, plastic and bullet fragments that would be jammed into my face.

rilyes had a super asinine setup trying to show off how BUIS can work through a optic with a bullet hole in it. well, provided you didnt get shot in the face while the optic was blown to hell, your best bet is to remove the broken optic and then put the BUIS on. looking thought iron sight BUIS though a broken scope friggen SUCKS.

rileys no longer has this, they took it off the rifle last month. it was a dumb demo in my opinion.

now, the way that photo has it, it appears that the rear BUIS is behind the ACOG, and the front one is in its normal position. if you have to use the BUIS, just take the ACOG off, which takes seconds, then flip up the BUIS.

and isnt that a back up optic piggybacking on the ACOG also?

 

[Andy in NH]

A.R.M.S. #40L

Rockrivr1,
Here is a picture of the A.R.M.S. #40L mounted under an RCO (ACOG).
The RCO is mounted on a LaRue Tactical ACOG Mount QD (LT-100).

The #40L is a little lower than the sight you have, which allows you to move the RCO back a few more slots in the M-1913 rail. I reversed the LaRue mount (for another reason), and this moved the RCO back just a little further also.

Please excuse the grainy picture, I zoomed in a bit.

In this set up, if the RCO was to become unusable, then you would need to flip the two levers on the ACOG mount and remove it. Next, trip the catch that holds the BUIS down and you are back in business (as long as you zeroed the BUIS prior to the engagement). If the threat is close enough where this would take too much time, then they are probably close enough for you to fire using body index / finger point (your terminology might vary) and still get good hits.

Neither the #40L or the LaRue mount are cheap. Both cost over $100.00, but they are rugged and reliable.