BUIS for LE6920

[Pinecone]

I have an LE 6920 (civilian M-4 for all practical purposes). Burris MTAC 1-4x on it.

I would like a set of 45 degree offset BUIS, but there is only a rail on the upper. I could change out the gas block, but wondering if there is any other solution.

Thanks.

 

[Skyyr]

If you really, really want to run 45* offset BUIS with your 6920, you can do it (it'll take some modification and/or replacement of parts), but it'll be painfully expensive to do so.

Is there any reason you're wanting offset BUIS compared to simply running a quick-release mount on your primary optic (if it's magnified) or using co-witness or lower 1/3 with a red-dot? Usually a 45* BUIS is used when you have a precision rig that performs poorly at close range, so it's easier to have a secondary sighting system than to try to use your primary sighting system at close range. With a 6920, it'd be hard to imagine using any kind of mid to high-power magnification with it that would preclude short-range use (they aren't intended for those roles in a combat situation).

 

[Shooter0311]

Dueck Defense RTS rapid transition sights or XS sight systems.
Dueck is sold from several places as well as the xs sight systems.

 

[elfster1234]

I think he only has one rail on the upper so the RTS transition sights would not work unless his handguard has a rail. You will need to look into either an offset micro aimpoint or micro red dot.

If you're handguard does have a rail, then definitely I would get the RTS sights as i have RTS sights on two different rifles that I currently own. Rts is bad ass and dependable.

Dueck Defense RTS rapid transition sights or XS sight systems.
Dueck is sold from several places as well as the xs sight systems.

 

[Shooter0311]

My bad gents. Good call elf. I was thinking le 6920 socom. I too have the RTS on 2 carbines and also have a set of XS 45 sights not mounted yet. The RTS is much more durable. (I would expect that from Barry Dueck.)

Cost effective dot on a 45 mount would be a trs25 on a good 45 mount.

 

[Skyyr]

My bad gents. Good call elf. I was thinking le 6920 socom. I too have the RTS on 2 carbines and also have a set of XS 45 sights not mounted yet. The RTS is much more durable. (I would expect that from Barry Dueck.)

Cost effective dot on a 45 mount would be a trs25 on a good 45 mount.

He wants 45* offset BUIS, not an offset primary optic. It doesn't really make sense to run a primary optic in a secondary position.

 

[Shooter0311]

His primary is a burris mtac 1-4x. Just ideas brother.

Your telling lots of folks with dots on 45's they don't make sense???? I am pretty fast and accurate with both my 45 docter sights.

 

[elfster1234]

He wants 45* offset BUIS, not an offset primary optic. It doesn't really make sense to run a primary optic in a secondary position.

i run RTS with my vortex 1-4power scope on my 3gun set up... I think the RTS would be the same as the micro red dot 1x? It is nice to keep the 1-4x power scope running @ 4x and switch over to the 1x micro red dot or RTS sight for close work 40feet or less as even ANY variable power scope at 1x will have some fisheye effect under 30feet.... . I'm not a fan of red dot magnifiers AT ALL... Then again, this is really all 3gun set up stuff. It is what berry dueck does with his 1-4 scope I think due to the fact you can only have one glass optic dependant upon the class you're running:

3-Gun Sight Options for ARs with Barry Dueck - YouTube

my 3gun set up minus the bipod in the pic:

very much a sub-moa rifle @ 100yards:

 

[Skyyr]

i run RTS with my vortex 1-4power scope on my 3gun set up... I think the RTS would be the same as the micro red dot 1x? It is nice to keep the 1-4x power scope running @ 4x and switch over to the 1x micro red dot or RTS sight for close work 40feet or less as even ANY variable power scope at 1x will have some fisheye effect under 30feet.... . I'm not a fan of red dot magnifiers AT ALL... Then again, this is really all 3gun set up stuff. It is what berry dueck does with his 1-4 scope I think due to the fact you can only have one glass optic dependant upon the class you're running

Correct, but in your case, your red dot is not your "primary optic" - your 1-4 variable is. Your red-dot is a secondary optic.

In the OP's case, he's wanting to run BUIS (literally Backup Iron Sights) - placing a red-dot offset, which would be the primary optic, makes no sense and he has to commit an extra weapon manipulation every time he uses the primary optic on the weapon.

 

[elfster1234]

I don't think you understand........ he only has one rail as stated in his OP.... what other options does he have?? what is he going to do?? run a RTS set up with the front and rear BUIS 3inches away from each other??? his only option is a micro red dot..... I guess I just don't understand your point here.....

unless he has some way of mounting the front offset iron sight which is hard to say without a picture of his rifle..... and you CAN NOT and SHOULD NOT mount jack to your gas block = getto and just the wrong way of doing things.... especially if you're gas block is at a different height than your main rail.

Correct, but in your case, your red dot is not your "primary optic" - your 1-4 variable is. Your red-dot is a secondary optic.

In the OP's case, he's wanting to run BUIS (literally Backup Iron Sights) - placing a red-dot offset, which would be the primary optic, makes no sense and he has to commit an extra weapon manipulation every time he uses the primary optic on the weapon.

 

[Skyyr]

I don't think you understand........ he only has one rail as stated in his OP.... what other options does he have?? what is he going to do?? run a RTS set up with the front and rear BUIS 3inches away from each other??? his only option is a micro red dot..... I guess I just don't understand your point here.....

unless he has some way of mounting the front offset iron sight which is hard to say without a picture of his rifle..... and you CAN NOT and SHOULD NOT mount jack to your gas block = getto and just the wrong way of doing things.... especially if you're gas block is at a different height than your main rail.

That was why I asked him what his intended goal is. Unless he just WANTS offset BUIS for the cool-factor, it's very pointless to use a 45* BUIS on that rifle. His best bet, if using a RDS/HWS, is to co-witness (or lower 1/3 align) his main irons through the optic. If his optic dies, his BUIS are ready to use.

If he's using a powered scope as his primary optic, then I'd suggest a quick-detach mount - that will allow easy access to irons if needed (after all, they are backup sights, not alternate sights).

The idea of mounting a sight in a 45*, non-optimal position JUST to be able to use the iron sights is counter-productive, as the optic will be his primary sight. This will teach bad fundamentals and poor shooting grips and stances, as well as muscle-memory.

 

[elfster1234]

totally 100% agree with you skyyr! what is the purpose of needing these BUIS.... if 3gun and keeping 1-4 power scope on 4x all the time, then yes... if mounting a 16x scope, then yes.. if doing it for a "cool-factor" especially when you're already running a variable power scope that can go down to 1x, then NO and save your money and keep the weight off your rifle...... unless you think you're going to be in combat and you absolutely need the BUIS, then save your money and keep the weight off the rifle. If all you're doing is punching holes in paper and general target shooting, then OMG, you might have to wait for your scope to come back on replacement warranty. Big question is, is there a war going on in your state? Hehehe, JK.

That was why I asked him what his intended goal is. Unless he just WANTS offset BUIS for the cool-factor, it's very pointless to use a 45* BUIS on that rifle. His best bet, if using a RDS/HWS, is to co-witness (or lower 1/3 align) his main irons through the optic. If his optic dies, his BUIS are ready to use.

If he's using a powered scope as his primary optic, then I'd suggest a quick-detach mount - that will allow easy access to irons if needed (after all, they are backup sights, not alternate sights).

The idea of mounting a sight in a 45*, non-optimal position JUST to be able to use the iron sights is counter-productive, as the optic will be his primary sight. This will teach bad fundamentals and poor shooting grips and stances, as well as muscle-memory.

 

[Crosshair]

Are you dead set on keeping the composite hand guards? If not, throw something like a Midwest industries Gen2 SS carbine modular rail on it and put the RTS sight as far forward as you can on the rail. They are pretty much the lightest aluminum rail on the market and will be even lighter that the composite guards due to eliminating the delta ring.
Midwest Industries: One Piece FF G2 SS-Series

Another option is to replace the FSB with a receiver-height railed gas block:
PRI Gas Block Single Picatinny Rail AR-15 LR-308 Standard Barrel .750

Or, go ahead and put a low-pro gas block and a full length rail on it, like the 15" Gen2 SS from M.I. (this is the rail I run) because of the increased sight radius and grip surface/length. This, to me, is the best option and I will be soon doing it to my 6920 to make it more like my recce rifle in feel/comfort and sight radius.

 

[Pinecone]

Interesting discussion.

The purpose is for 3 gun use. Normally, I would dial the MTAC up or down in power, but understand that some courses are better served by off set iron sights for close in targets, keeping the scope dialed to a higher power. Time and grip factor to dial up or down.

When I bought the MTAC, I got the combo with mount and Fast Fire II red dot sight. A BIG kudos to Sport Optics for dealing with my questions and a GREAT price. The stock setup has the red dot mounted above the scope. But two optics, pushes into Open class, and I don't want to go there.

I see eventually a new handgaurd and gas block is in my future, but the funds don't support it at this time.

I did find this - RK-M4 Fore End Rail Mount :: HOLSTERS.com

Made by Safariland, it attaches to a stock A2 type handguard, but adds rails, including a 45 degree rail. Seems like the ticket for now.

 

[elfster1234]

it would be the correct way of doing it and would make the rifle more accurate anyway... get the free float handguard with a railed top, and THEN mount the RTS up front.... then you'll be tip top

Interesting discussion.

The purpose is for 3 gun use. Normally, I would dial the MTAC up or down in power, but understand that some courses are better served by off set iron sights for close in targets, keeping the scope dialed to a higher power. Time and grip factor to dial up or down.

When I bought the MTAC, I got the combo with mount and Fast Fire II red dot sight. A BIG kudos to Sport Optics for dealing with my questions and a GREAT price. The stock setup has the red dot mounted above the scope. But two optics, pushes into Open class, and I don't want to go there.

I see eventually a new handgaurd and gas block is in my future, but the funds don't support it at this time.

I did find this - RK-M4 Fore End Rail Mount :: HOLSTERS.com

Made by Safariland, it attaches to a stock A2 type handguard, but adds rails, including a 45 degree rail. Seems like the ticket for now.

 

[elfster1234]

it would be the correct way of doing it and would make the rifle more accurate anyway... get the free float handguard with a railed top, and THEN mount the RTS up front.... then you'll be tip top

BTW, you really shouldn't mount anything to a 2pc, non-floating, handguard other than maybe lights / grip-pods... you should never mount any type of glass/optic/buis to a 2pc, non-floating hanguard... that is why I always try to get an AR with a minimum freefloat handguard, unless I want it for maybe an ultra light weight home defense set up or something... it really is all about intended purposes.

 

[Pinecone]

I wonder how bad it would be to mount to the handguard for use under 50 yards.

 

[elfster1234]

My very first ar was a dpms oracle because i didnt know any better and it had a non-freefloat 2pc plastic glacier handguard... At that time i didnt know shit about ar's (and some would say i still dont LOL). Then i replaced the plastic 2pc handgaurd with an ultra cheap quad rail like most do when first getting into the ar rifle game. Now i somewhat live by the "buy once cry once method" and to make damn sure any ar i purchase has a freefloat tube..... 2pc non floating handguards might wiggle to much if you want to make sure your optic or buis is accurate. To mount any type of optic or buis to a 2pc handguard is screaming ghetto. I just would not do it..... Getting into the AR game is really a live and learn sport / hobby.

I wonder how bad it would be to mount to the handguard for use under 50 yards.

 

[GeorgeD]

I run a set of Knights armament 45° flip ups on my .308, I like them a lot. I like the flip capability for storage and cases, but I've also used the Dueck Defense sights and I like those too. The XS sights don't look to bad either though I have not used a set so I can not offer an opinion on them.

As far as mounting the sights, I would opt for a free float tube. There are a lot of them out there, many quality units, take your pick. Not only would it give you a mounting solution but more real estate to get your support hand farther out on the gun.

If a free float is not something you want to invest in maybe a clip in rail is the way to go. Knights, Daniel Defense both make direct replacement carbine length rail systems that would work with your carbine. Both will give you a mounting surface on the same plane as your upper costing around $150 last time I looked.

Good luck,
George

 

[pmclaine]

Something like this

JP - Detachable Sights

but you would need some 45 degree mounts to get it on the side of your upper. Might get a little bulky.