If you own a tactical style carbine which do you prefer in conjunction with a red dot and why? I’ve noticed that many members have a folding style and some have fixed. I’m in the market for one to add to my carbine and the two I’m looking at aren’t exactly cheap; the Larue BUIS or the Troy flip up BUIS.
Brandon
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I have a new Eotech XPS on a Larue riser mount with a fixed Larue rear sight. The rear sight has the XS Paul Howe CSAT sight and a white line/tritium front. I really like it ( I work night shift as a cop)
The Larue mount gives a 1/3 co-witness with the Eotech and iron sights. I see very little difference when the rear sight is there or removed ( it is QD).
But this would not be true without a riser because it would be absolute co-witness and in my opinion cluttered.
Are you gonna run optics? If so, are you gonna use a riser?
If no optics, then definitely get the fixed.
Also depends if you have a fixed front. Lot of variables.
I like being able to instantly deploy iron sights and also check my zero on my Eotech.
By the way, the Larue is a first class rear sight. So etimes I remove the QD Larue/Eotech just so I can use the iron sights.
What is your application of your rifle?
My rifle is just going to be a tactical style carbine. I don’t work LE or military just a civilian looking to get into the world of black rifles. It will eventually sport an Aimpoint ML2 or 3 on a Larue M68 CCO mount(non cantilever.) The reason I asked fixed vs. folding is because if you are presented with a highly tense situation do you want to have to take the time to deploy your rear site or just already have it waiting?
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Larue also offers a QD fixed rear BUIS- maybe that was what he was contemplating purchasing.
You are correct Frank.
I may be wrong, but a folding and flip up BUIS are the same. I assume the title should have been folding vs. fixed BUIS.
Negative.
Ah…Yes, you are correct sir. Should have been, “FOLDING vs. FIXED BUIS.” That was my error.
BTW: Corrected.
It’s personal preference really.
Try shooting each if you can before you buy.
I personally run a Daniel Defense Fixed A1.5 rear on my 10.5" SBR and a Magpul MBUS on my 16" Middy. Both are run behind Aimpoints (an H1 on the SBR and a C3 on the 16") in a lower 1/3 co-witness setup. Both employ standard foxed front sights.
My reasoning is this… Within the distances that the 10.5" SBR is most effective, I do not want to have to take a hand off of the weapon in the event I need to deploy a BUIS. In these CQB distances I prefer to be able to immediately transition to the irons. Where as with the longer rifle the intended deployment ranges MAY more readily facilitate the transitioning to a secondary or immediate deployment of a folding rear sight depending on the particular situation. That said, with either setup the aimpoint body could be used as a make shift ghost ring rear with the fixed front sight to put rounds down range until a BUIS could be deployed.
Again these are just my preferences on these guns, and either rear would be effective on either weapon. I chose the Daniel Defense and Magpul offerings because I found each to be a robust, well though out, and cost effective solution. I do not see the need for QD on rear sights, and therefore prefer not to pay extra for that feature. I also prefer my folding sights to lock in the stowed position and not lock in the deployed position, and instead rely on spring tension for rapid deployment, maintaining an upright position, and aiding in absorbing potentially damaging blows (especially helpful given the polymer construction of the MBUS, although I haven’t seen any broken in this manner yet).
Again, I fully recommend that if at all possible you try as many as possible before you make your selection. And if you are unsatisfied, there is always the for sale section! 
Good luck!
-RD62
Thanks RD. Very insightful post.
Brandon
I too use a Larue fixed BUIS w/ XS CSAT rear aperature and factory front sight with XS stripe front site. I bought the Larue before I had an Aimpoint but the sight does not get in the way of my FOV. The iron sites line up in the lower 1/3 of the Aimpoint and the red dot is upper 1/3.