View Full Version : Help me with a BUIS system
I have a Colt 6920 LE 16" M4 type rifle with removable carry handle. I want to put an opticle site on it and also have a back up iron sight system (BUIS). I thinking I can do the following:
1) replace front site with a railed gas block
2) put an eotech or aimpoint on an ARMS #19 throw lever mount
3) add flip up front and rear BUIS.
I'm thinking that if my optics fail I can simply throw the levers and remove and pop up the BUIS. What do you think?
(I've been to AR15.COM and read the BUIS thread)
Ever think of a fixed rear BUIS??
Take a look at the LaRue fixed BUIS.
best thing going in fixed BUIS's.
The setup I like is an EOTech with a Larue mount and a Troy folding rear sight. I would leave the FSB in place.
All of mine retain the standard front iron sight. My favorite folder is the Troy. The ARMS 40 is good as well. If you battery optic fails when you’re in the mix, you won't have time to mess with throwing a lot of levers and flipping irons up. I mount all my battery powered optics directly to the flat top upper. If they fail, they stay in place and I only have to snap up the rear BUIS. You can view the irons through the Aimpoint or EOTech, no need to remove them.
G37 Commando
10-06-2005, 18:14
ARMS #40 or #40L
Jay
switch625
10-06-2005, 18:22
Are you going to add a red dot or a scope? Not sure about a scope, but the front site will disappear using a red dot. If you still want a folding front, add one later. I would suggest the Arms 40A2 for a BUIS.
Bushw@cker
10-06-2005, 22:56
I have an ARMS #40L, and it is a very good sight. The #40 wouldn't be a bad way to go either, just depends if you want a low profile or not.
http://img189.imageshack.us/img189/8536/arfall3ny.jpg
demusn79
10-07-2005, 05:48
arms40l and gg+g very nice also!
http://i22.photobucket.com/albums/b317/demusn79/th_Im000389.jpg (http://i22.photobucket.com/albums/b317/demusn79/Im000389.jpg)
;a
I have to agree with other posters here. I would keep the standard front sight and cowitness the sits. I'd also suggest an ARMS #40 (L wouldn't be bad, but I'd suggest the #40 since you don't have to clear the optic).
Michigun
10-07-2005, 06:54
I say keep the front sight base/gas block as is… that way you could use your dead optic as a big, fat “ghost ring” in a pinch (It actually works REAL well out to at least 50 yards!)… that’ll keep you shooting pretty accurately till the time in which it is “tactically sound” to flip up you rear BUIS… if you have a front BUIS folded, & your optic dies, you’ve got no accurate fire until you stop & at LEAST flip up the front BUIS. Besides, ALL non-standard front sight bases/gas blocks look out of place & down right ugly IMHO. ;)
dbrowne1
10-07-2005, 09:12
1. Keep the FSB.
2. Don't use ARMS (mounts or sights). Their quality is very poor compared to other brands available these days. They use brittle MIM throw levers that can break, and their rear BUIS has had some issues as well.
3. Use a LaRue mount for your sight.
4. Use a LaRue fixed BUIS or a Troy folding BUIS.
I say keep you front sight and your carry handle and mount a compact acog 2x or 1.5x red triangle on your carry handle.
Michigun
10-07-2005, 12:06
Originally posted by Britt
I say keep you front sight and your carry handle and mount a compact acog 2x or 1.5x red triangle on your carry handle.
Not a big fan of "cheek weld", eh?
dsg2003gt
10-07-2005, 14:17
the TROY sight is actually not that great. When tightened down the sight lifts the right side, and needs lots of windage adjustment to zero.
I have seen that on 3 of their sights.
Originally posted by Michigun
Not a big fan of "cheek weld", eh?
big fan of cheek weld but the compact ACOG's are made for the carry handle
Keep the standard FSB.
If you like a fixed rear sight, the Larue or LMT are excellent choices. For folding, ARMS, Troy and several others are available. Personally, I run a ARMS 40A2.
A_Swede_17_1911
10-10-2005, 15:01
If you go with the Aimpoint, just get the the quick detach aimpoint mount, and get a Knights BUIS, its dead simple and it works. It co-witnesses, pefectly. Its not the most fancy set up, I know. It works and that to me is what matters.
This is the same system that the Army is currently using. Or you can mount just the EO Tech, and the Knights BUIS and it will co-witness as well. I just like the round tube of the Aimpoint when using the Iron sights.
Only thing that might give you some fits on the Knights is that you can adjust it for elvation. Only windage, its that simple and it works. You just change the elevation with the front sight post and zero to the 300M battle zero standard. You would do that at 25Meters.
Ive used both the EO-Tech and the Aimpoint with the Knights BUIS, and it works well. Also you can put dab of superglue on the insert if your worried about it falling out. Which it does only if you are playing with it and trying to lose it.
Atty_Guy
10-11-2005, 22:01
Troy BUIS. Only way to go!
I don't really see any advantage to cowitnessing irons with a dot sight. Think about it. Either your optic is going to be alive, or it's going to be dead. If your optic is alive, and you're cowitnessing, you now have to align three objects (front/rear sight + red dot) with your target, instead of one (the red dot), and you've just defeated one of the major advantages to a red dot (simpler sight picture). So why bother, if your optic is alive you'll just use the dot anyway. But if you're optic is dead, and you have to transition to irons, whether or not your irons are cowitnessed with your optic is irrelevant because your optic is, um, dead. If the irons are sighted, and if you can view them properly through the optic, then flipping up the rear BUIS and reacquiring sight picture through the irons is going to take the same amount of time regardless of whether or not they are cowitnessed with the optic.
demusn79
10-12-2005, 16:38
co witness you don't have to line up your iron sights you ignore them,you can check your POI is aligned by lining up the three.the dot will be right on top of your front sight post.
Originally posted by demusn79
co witness you don't have to line up your iron sights you ignore them,you can check your POI is aligned by lining up the three.the dot will be right on top of your front sight post.
yeah you do gain that bit of convenience. but what's cheaper, spending money to get the spacers etc for proper cowitness so that you can have that convenience, or filling a mag up and zeroing your irons :) i mean, if you have irons, you ought to be able to shoot with them, no??
dsg2003gt
10-12-2005, 20:59
Originally posted by yahkohb
I don't really see any advantage to cowitnessing irons with a dot sight. Think about it. Either your optic is going to be alive, or it's going to be dead. If your optic is alive, and you're cowitnessing, you now have to align three objects (front/rear sight + red dot) with your target, instead of one (the red dot), and you've just defeated one of the major advantages to a red dot (simpler sight picture). So why bother, if your optic is alive you'll just use the dot anyway. But if you're optic is dead, and you have to transition to irons, whether or not your irons are cowitnessed with your optic is irrelevant because your optic is, um, dead. If the irons are sighted, and if you can view them properly through the optic, then flipping up the rear BUIS and reacquiring sight picture through the irons is going to take the same amount of time regardless of whether or not they are cowitnessed with the optic.
if everything is correctly sighted in, the dot and irons will be the same looking through them, so you dont necessarily have to line all 3 up. Just the irons..and the dot will be dead on with them.
Kinda retarded to run irons and a dot at the same time tho in the up posistion. but if you are kicking down doors and you might need irons, leave them up and all you will have to do is shift your head down if the dot goes out.
Originally posted by dsg2003gt
but if you are kicking down doors and you might need irons, leave them up and all you will have to do is shift your head down if the dot goes out.
i agree, but the subtle point to remember is that your ability to leave your irons up and shift your head down if the dot goes out has nothing to do with whether or not the irons were initially cowitnessed with the dot.
demusn79
10-12-2005, 23:52
Originally posted by yahkohb
yeah you do gain that bit of convenience. but what's cheaper, spending money to get the spacers etc for proper co witness so that you can have that convenience, or filling a mag up and zeroing your irons :) i mean, if you have irons, you ought to be able to shoot with them, no??
EOThingie mounts directly to flattop for proper co witness.
;Q
http://i22.photobucket.com/albums/b317/demusn79/th_IM000419.jpg (http://i22.photobucket.com/albums/b317/demusn79/IM000419.jpg)
If and when i decide to put a red dot on my AR, I am just going to chop the carry handle.
Michigun
10-13-2005, 06:10
...
dbrowne1
10-13-2005, 15:33
Originally posted by dsg2003gt
the TROY sight is actually not that great. When tightened down the sight lifts the right side, and needs lots of windage adjustment to zero.
I have seen that on 3 of their sights.
Didn't notice that on mine. Also, don't see how it would lift even if overtorqued, but you don't need to torque the screw that holds it that hard if you use loctite.:)
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