Prior to plans of a new build, I have only been a flip up BUIS user and would like to know what advantage a permanent co-witness gives, other than a seamless transition if your optic bugs down.
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Prior to plans of a new build, I have only been a flip up BUIS user and would like to know what advantage a permanent co-witness gives, other than a seamless transition if your optic bugs down.
Besides the easier transition, they are also less parts to break. Quite a few people have deployed various spring-loaded BUIS over the years only to find them stuck at half-mast for reasons relating to spring fatigue as well as gunk stuck in the sight gumming up the works.
A fixed rear BUIS is always there all the time. obviously the biggest downside is incompatibility with some optics and magnifiers.
Another incompatibility that could exist, could be with the user.
At one time I used the combination of CCH BUIS-EOTech-STD FSB. Regardless of how hard I concentrated on the target, hoping that all other objects in the FOV would fade out, the FOV was simply too cluttered for me. :(
I've had a few guys that come out and shoot with us complain of the cluttered view. I've never had one maintain that complaint after shooting with us for awhile.
I shoot an SBR with a T-1, fixed FSB, and a Larue rear BUIS. this is about as cluttered as you can get given the smaller tube size of the T-1 than other Aimpoints, or the Eotech "screen". In fact I shot this gun this past Tuesday night in our match. At no point did the iron sights even register on my brain, as I was using the optic correctly and focusing on the targets. In fact, when focusing on the target, I find it difficult to even register the iron sights, front or rear, at all.
(I need to work on more pictures of this phenomena)
However, the above setup with T-1 in Larue mount does provide for a lower 1/3 cowitness which may help. given how low that the Eotech sits when mounted directly to the flattop I could see a potential issue with fixed sights. IMHO the better fix there is to ditch the sub-par optic. YMMV
You’re correct Sir, I imagine with more time, I could have MADE myself get used to the set-up, but again maybe not. I think as individual as each of us are, so are the ways our eyes and brain gather and process this type of information.
For some it might be an easy process. For others it may take time. Or again, for some, overcoming the problem may never happen.
I kept telling myself to just get used to it. It’ll come with time. But since I had no need to force myself to get used to and adapt to this set-up, the choice was a simple one. Get rid of the CCH BUIS, and go with a folding BUIS.
I had a ARMS#40 BUIS and I swapped it out for a Larue fixed BUIS. The ARMS BUIS I had to adjust the windage 3/4 of the way to the right to zero it. The Larue fixed BUIS required less than 1/4 turn of the windage knob from center to zero it. [ Not a problem really but I thought that was nice that it zeroed up in the center of the sight]. Also picked up a Larue LT-150 aimpoint mount. I was worried at first about a cluttered sight pic but now I believe it will work out good once I get my aimpoint.
Sorry not much help but its my experience so far.
Thanks everyone. Will try shooting a bit more with my BUIS up to see how it feels and possibly, if I see myself getting used to it if it gets in the way.
I've been shooting with FSB, DD rear BUIS, and T1 in a ADM lower 1/3 mount. I'm yet to find the fixed front to be an issue and as several have said it really almost disappears. As for the rear, while I won't say it obstructed my view or distracted me, I did definitely notice. Perhaps given enough time and practice as Rob said it would be completely unnoticeable much like the front. That being said I have recently switched to a rear Magpul MBUS flip-up to see if I like that view better. Depending on how I like it, I may or may not switch back to the fixed DD BUIS. The front is definitely not an issue though and at the current moment I see no reason to go with a flip up front and add 1 more thing that could possibly go wrong. Just my $0.02
I love it!
I may however migrate thie 14.5" to an ACOG with a Troy flip down rear, and move the T1 and LMT rear to the 10.5" SBR I have in the works. The sight picture would be identical to what I have now. I really just prefer a fixed front and rear irons when using a 1x dot sight.
I ran a conventional FSB, Comp M2, LMT Rear for years and never had any problems with the irons despite numerous classes and pig hunting. I recently picked up a Troy flip-up rear and haven't found much difference between it and the LMT - my mind just blocks out the extraneous info (just ask my wife).
I do like an absolute cowitness with my optic as it is a very functional BUIS.
Something I dont like with the BUIS that came with my M&P is that the rear BUIS you have to flip the sight to the large aperture in order to fold it flat. I do almost all of my shooting through the small aperture so this is a bit frustrating for me. Anyone know of a BUIS that has the small aperture that you can mount flush?
I will have to look into the magpul version. The current incarnation on my rifle just ticks me off makes me want to rip it off and chuck it. How do you make something you cant leave adjusted to you no matter which aperture you want. Must have been made by a designer and not an end user....
Matt
While opinions vary, there is a sound theory behind having the big aperture be the default on a BUIS. The idea is that if you really need the BUIS right this minute, chances are good that it's a close-range threat and you will want the big aperture. If it's a longer range threat, you have time to change to the small aperture if you need/want it.
Personally, I wouldn't get wrapped around the axles about it. The Troy BUIS is the best flipup I've seen or dealt with. Even if I thought I wanted it to default to the small aperture (I don't) I would still pick it over other options because of the other features it offers and I'd learn to deal with the minutia of the aperture issue.