[jademac]

^^^^

Definitely agree, especially when I saw the measurements. Therefore, I went for the RB Precision (http://www.rbprecision.com/) short rail with dovetail mount made for the Sig 556 instead. Better quality, more durable, & very sturdy as you can see from my previous pics...

 

[jd]

^^^^

Definitely agree, especially when I saw the measurements. Therefore, I went for the RB Precision (http://www.rbprecision.com/) short rail with dovetail mount made for the Sig 556 instead. Better quality, more durable, & very sturdy as you can see from my previous pics...

Hi Jademac

I got the rail piece of off ebay....its ok but yes would like a sturdier option if available.

If I may ask...Is the RBP the same height as the Sig factory receiver rail? From your pics the thickness makes it seem a little higher.

Thank you

JD

 

[jademac]

That is correct, more sturdy, but just a tad higher. Had to adjust the windage & elevation on the Magpul MBUS to zero in the carbine at 50 yards. Took some time to get it zeroed, but all is good now! As long as your sights are adjustable, you should be good, too!

 

[Draxanoth]

That is correct, more sturdy, but just a tad higher. Had to adjust the windage & elevation on the Magpul MBUS to zero in the carbine at 50 yards. Took some time to get it zeroed, but all is good now! As long as your sights are adjustable, you should be good, too!

Jademac did you file down your RBP dovetail adapter to get it to fit with the quad rail?

 

[WpnsMan]

If the RBP dovetail adapter will work within the elevation adjustment range of Troy Micro’s while achieving a proper cheek-weld on the factory or AR adapted stock, I think I may have found the perfect solution to overcoming the last stumbling block with the system before buying a classic 556.

Anyone try that combo yet?

(Edit 6 Jan) Jademac,

Just went to the RB Precision website via the link you provided and this adapter is not listed under their Sig accessories or the RB manufactured parts. If it is still available I wonder where they're hiding it on the website?

Wpns Man

 

[jademac]

I actually had to call RB Precision, because I also did not see it listed on their website. I told them I had a Sig 556 & it was ordered the same day, fast shipping too! It was inexpensive & now my choices for front sights have definitely grown. Depending on the type of Sig 556 you have, there may need to be some modifying of the actual dovetail mount. For example, one end of my dovetail mount (the end without the RBP logo) was filed down via dremel for it to fit snugly with my quadrail. Once done, it fit nice & snug! I think with the Sig 556 Classic, no filing has to be done. In addition, the cheek riser feels like it helped get my sighting done easier. Good luck!

 

[Draxanoth]

I actually had to call RB Precision, because I also did not see it listed on their website. I told them I had a Sig 556 & it was ordered the same day, fast shipping too! It was inexpensive & now my choices for front sights have definitely grown. Depending on the type of Sig 556 you have, there may need to be some modifying of the actual dovetail mount. For example, one end of my dovetail mount (the end without the RBP logo) was filed down via dremel for it to fit snugly with my quadrail. Once done, it fit nice & snug! I think with the Sig 556 Classic, no filing has to be done. In addition, the cheek riser feels like it helped get my sighting done easier. Good luck!

Thanks Jademac, I was pretty sure you had to have modified yours, but I thought maybe they had a different style I didn't know about. I haven't decided to replace my front post yet, waiting to see what the MBUS2 looks like, but I'm prepared with an adapter in the event that I do. =)

 

[jademac]

Yes, the Magpul MBUS2 looks reel sleek...coming out in the spring, unless you buy the Magpul ACR that comes stock with these 2nd generation sights. I like how the Magpul logo is on the flip portion & that it says MBUS on the sides, plus it is more flush to the rail...nice!

Here's the link: http://www.magpul.com/assets/files/2010Catalog/3-MOE.pdf

8)

 

[WpnsMan]

Jademac,

Thanks, wonder why RB Precision doesn’t list this in an easy to find spot on their web site. Glad it is working out for you but, I don’t want to use AR height sights and a cheek piece to get a proper cheek weld.

Has anyone used the Troy Micro’s I mentioned before with this adapter?

The lack of standardization from Sig in regards to iron site height and the justifiable hesitance of in the aftermarket to design and produce compatible options until they do is convincing me that this system is not yet ready for serious consideration.

While promising, there are just too many reports of spotty quality control which seems to be a common denominator in all of Sig’s products over the last few years, and ill conceived (though well intended) work arounds to problems that could have been avoided if Sig would have refined the product prior to putting it on the market.

I am NOT trying to bash Sig. Hell, my go to/carry guns rotate between a P220 and a P6 (both West German production). I just wish Sig USA would get their act together with the 556 and hopefully the 756 before it hits the streets.

Wpns Man

 

[Draxanoth]

Jademac,

Thanks, wonder why RB Precision doesn’t list this in an easy to find spot on their web site. Glad it is working out for you but, I don’t want to use AR height sights and a cheek piece to get a proper cheek weld.

Has anyone used the Troy Micro’s I mentioned before with this adapter?

The lack of standardization from Sig in regards to iron site height and the justifiable hesitance of in the aftermarket to design and produce compatible options until they do is convincing me that this system is not yet ready for serious consideration.

While promising, there are just too many reports of spotty quality control which seems to be a common denominator in all of Sig’s products over the last few years, and ill conceived (though well intended) work arounds to problems that could have been avoided if Sig would have refined the product prior to putting it on the market.

I am NOT trying to bash Sig. Hell, my go to/carry guns rotate between a P220 and a P6 (both West German production). I just wish Sig USA would get their act together with the 556 and hopefully the 756 before it hits the streets.

Wpns Man

I would guess RB no longer lists them because they no longer make them.

Considering not a lot of people have the adapters I doubt you're going to find answers to every question about compatible irons. Based on Jademac's experience I would assume any paired set that has a rear you can adjust, to make up for a possible 1-2mm difference in forward height, will work. RB made their adapter for one set of Sig rails, Sig has changed rail systems a few times, so it's not surprising it doesn't sit even with all of them.

Judging by your overall posts it doesn't sound like a Sig556 really meets your expectations though, pretty much every time you ask about something you explain why it's not worth buying.

Personally, I love mine, but I got it for an excellent price. I think a Sig at $1800 is probably too much considering; but if you can snag one now for $900-$1000, before they eliminate the excess and prices go back up, I don't see an issue. In my case I'd likely end up replacing half of the components on any rifle I buy; so getting a Sig for less where that process is mandatory, vs. a more expensive rifle where it may not be, seemed to make sense to me. Then again I haven't had the accuracy issues some others have suffered so part of my satisfaction may be purely luck of the draw.

 

[WpnsMan]

Draxanoth,

Have you confirmed that RB Precision is no longer making their adapter. That is not what I gathered from jademac’s post. I could see if it is a discontinued item that they no longer list but still have in stock if you ask. To bad if they did, as I said before, it seems like a solution to part of the iron sight issues people are having.

I was looking at this option before deciding whether or not to buy a non-railed classic. Sig changing their railed handguards isn’t really an issue for my intended application.

I’ve never said it wasn’t worth buying and I don’t think my expectations are unreasonable. From reading post on this and other forums, it would seem I’m not alone.

If you’re happy with yours the way you have it set up, what’s more to want, glad you’re happy. I don’t mind spending money on “fixing” the things I don’t like either so, the price isn’t an issue. The issue is the pieces necessary to achieve my needs are not currently available.

I will be using either my Aimpoint or ACOG on this rifle. I need a folding rear sight that will fit under an ACOG or can be folded down when using the Aimpoint as I don’t like having a rear sight in my field of view.

The only rear that currently meets that requirement is a Troy Micro. However, it is not compatible with the Sig fixed front as there would be no way to zero the sights for elevation. The Aurora fixed front is adjustable but, up to this point I haven’t seen reports of anyone using one with a Troy Micro rear to know if that combination is compatible or not.

This brings me to the conclusion that I would need an adapter that will place a folding front sight on the gas block at the same rail height as the receiver for use with a compatible folding rear. Or, one that is close enough to still work within the range of adjustment to properly zero the rifle. Preferably Troy Micros to get a proper cheek weld.

I have inquired with Troy about making a dedicated gas block mounted Micro front and have received no response to date.

Using AR height sights are not acceptable to me because you either end up with a chin weld or have to buy a cheek piece for whatever stock you are running to avoid it. So, using MI or Samson folding front sights don’t meet my needs either.

Wpns Man

 

[Draxanoth]

Draxanoth,

Have you confirmed that RB Precision is no longer making their adapter. That is not what I gathered from jademac’s post.

I have inquired with Troy about making a dedicated gas block mounted Micro front and have received no response to date.
Wpns Man

I did not specifically ask them, but when I bought mine the rep gave me the impression they weren't planning to produce more, and the ones they had were the few they had left. =/ My point was if you need one I would get one sooner rather than later since they may not be available.

I wish you luck with Troy. Personally I like having the rail compatibility up there. Lets you use any rail mounted iron you want, and if you ever decide to sell the rifle you have the option of keeping your BUIS if you want them vs. being forced to give up a forward that is only compatible with the Sig, or trading irons between rifles if you find you like one better than the other. Etc. I like options. =)

 

[WpnsMan]

Thanks for clarifying that their adapter has indeed been discontinued.

I don't mind the thought of a dedicated front, folding or fixed as long as it meets my needs.

I have Troy rears on a couple of AR's and prefer them to everything else out their. I replaced the issued Matech on my M4 with one during my first tour in Iraq and have been sold on them since. Their Micro would seem to be the rear I'm looking for on a 556. Being something I'm familiar with is a plus. Yeah, I hope to hear something positive back from Troy but, I'm not holding my breath.

I'm starting to think the factory Sig fixed front and the lolly pop rear are my only viable options.

Wpns Man

 

[jd]

This is my solution which is still a work in progress

I stuck with the ebay picatinny rail piece...although I plan on taking it to a smith and seeing if he can reinforce it buy adding a weld. Really I probably wouldn't mind if I have to perm attach it some way (silver solder) to the gas block as long as it is level with my rear rail and sturdy.

For sights I researched around I decided to try these

http://www.robertrtg.com/416sights.html

And how they look:

I still have not had a chance to get it to the range, but if I can make this work, the HK416 sight height is ideal. Cheek weld is perfect for me.

WpnsMan, afaik, the troy micros were designed for higher profile receivers like the 556. So they should work, BUT I do not think the troy rear matches exactly with the Sig fixed front Titan claims they made them in part for their 415 uppers.

http://www.titandefense.com/sights.html


What I have not tested is could one use a combination of the HK fixed with Troy micro folding.


Edit:

Attached quick non scientific comparison of sight height

- Sig backup for hooded front sight

- HK 416

- Troy folding rear BS (regular height)

 

[767fixer]

will the Magpul Mbus melt on the gas block if you use an adapter???

 

[Draxanoth]

will the Magpul Mbus melt on the gas block if you use an adapter???

I myself haven't had any melting, but I haven't put multiple hundred rounds through in a single sitting either.

Jademac have you had any melting occur on yours?

 

[jademac]

I have put around 100-150 rounds of Lake City 5.56 - M855 ammo (http://www.palmettostatearmory.com/725.php) through my Sig, during multiple range visits with friends also shooting my carbine. No melting issues with the Magpul MBUS so far.

 

[Sturmgewehr]

Save your money. This thing is VERY flimsy.

I mounted it, and it looked like a very good fit in the dovetail. Then I tigtened the screw and it nearly pushed the mount straight up right out of the dovetail. I applied a bit, and I mean a very small bit, of pressure to the rail with my thumb, and it bent quite easily.

I would NEVER trust this rail to hold a sight on a rifle I expect to trust my life to. No way.

I took some measurements with my admittedly old vernier caliper. Pay attention to the 1mm measurement. It's just not enough material for an aluminum rail. I'm not even sure it would be sturdy enough if it was made out of steel.

Let's see if I know how to post a pic here.

I have to agree, this is not the way to go--you will better off with the gas block mount.If this were such a great
idea the Swiss would be using it. The gas block is MUCH more solid. Pete

 

[jb76]

I actually had to call RB Precision, because I also did not see it listed on their website. I told them I had a Sig 556 & it was ordered the same day, fast shipping too! It was inexpensive & now my choices for front sights have definitely grown. Depending on the type of Sig 556 you have, there may need to be some modifying of the actual dovetail mount. For example, one end of my dovetail mount (the end without the RBP logo) was filed down via dremel for it to fit snugly with my quadrail. Once done, it fit nice & snug! I think with the Sig 556 Classic, no filing has to be done. In addition, the cheek riser feels like it helped get my sighting done easier. Good luck!

yes there is modification when it came to my patrol.I have the polymer forends and retaining ring.I had to dremel off each end so i can basically have just one piccatinny groove.that is all i needed though.i also had to dremel my magpul front flipper.i got it to work though.went to range today and 1/2" at 50 yards indoor.sighted in perfect.sturdy too....BE SURE TO LOCTITE THAT GRUB SCREW!!

 

[bossgvr4]

Reports of the demise of this adapter have been GREATLY exaggerated .... I just ordered one ! Planning to mount Troy Micros in the upcoming weeks. (NOTE the extended top rails towards the bottom of the page)

http://www.rbprecision.com/id116.htm