Got my new SIG516 in FDE today and I immediately noticed the gas block is very different. Not necessary bad, just different. I called SIG and asked them why my gas block is designed differently than what is pictured on the website and from what I've seen on this forum from other owners. The tech said it is different b/c SIG wanted to have/be able to use the same gas block/valve as the new SIG716 and I got one of the "new" rifles. I'm fine with that, I just wanted to know why. BTW...my SIG516 FDE has a born on date of 6/5/2012. Also, there are no "tooling" marks on my bolt carrier from when SIG changed their bolt carrier design (almost sued by LWRC). It looks very nice. I saw some pretty bad tooling marks from when SIG516 owners sent in their LWRC copy bolt carriers to SIG to get "revised".

The tech also said that there is a revised owners manual that shows the NEW gas block/valve design. Mine did not ship with it so he sent me a PDF copy. Now, I also noticed after taking the gas piston and valve out of the rifle that there are NO THREADS OF ANY KIND associated with the gas system. I've been reading tons of reviews by you folks that mentions how the gas valve threads into the gas block and how some folks don't like the threads, but I don't see threads ANYWHERE on this new design. Everywhere is smooth. You will also notice from the pictures that you no longer have to use the tip of a bullet or tool to press the detent to change the gas setting. You just press the big button with your finger and rotate the valve by hand (it's very stiff, so a bullet may help).

Another thing I noticed and have a question about are the gas settings. There are 4 settings on my gas valve as you can see on my photo. According to the manual the large hole is for Normal operation. The medium hole (valve at 12 o’clock) is for adverse conditions (it's in adverse in the picture). The small hole is for suppressed. X is off single shot.

For some reason I would think the large hole would be adverse and the medium would be normal. Are my settings the same as your settings? I always thought NORMAL SETTING was when the valve is in the vertical (12 & 6 o'clock) position. I'm thinking there is an error in the new manual the tech emailed me and the photos showing Position 1 and 2 were accidently switched.



Gas setting is at Normal in this pic.




Adverse setting in this pic (valve is at 12 o'clock).


I think this snapshot from the new "revised valve" owner's manual has the pictures switched incorrectly.



Notice in this snapshot of the "old" owner's manual it's switched. Valve in the vertical position is Normal setting.

Sweet!  I have a 516 with the older gas block and the 716 with the newer block.  I'm sure it does simplify things at the factory but I think it is an improvement over the older style since it doesn't require all the unscrewing to get the gas valve out.  My compliant with the older style is that is was kind of a bear to unscrew once the threads were fouled with a little carbon.

Congrats on the new blaster.  It looks great!

Melvin,

Can you confirm this picture is WRONG?

I wish I had a definite answer for you but I don't.  The markings on the new 516 block are different from the markings on the old block and also somewhat different from the markings on my 716.  With that said I'm going to say that the small dot means suppressed, the middle dot is for regular service and the big dot is for fouled or cold weather use.  That's how the dots are laid out on the rifles I've got.  

That's EXACTLY what I'm thinking. It only makes sense. Why would a large hole be Normal setting and the medium hole be Adverse?? Simple mistake in the manual I believe.

I'm sure it is a misprint.

Anyway, this is a great thing for the 516.  Now we need someone to introduce a slightly longer handguard that extends out over the sides of the gas block to help isolate fingers from a hot part and to give a little additional real estate for accessories.

I totally agree. I'm going to have to use a vertical grip on this sucker so I don't burn my hand.

Wow, they did change that quite a bit.  I have one of the very early models that had the recalled bolt carrier, of course they didn't give a reason for the recall way back then, otherwise I would have kept it LOL.  They are great guns, I'm sure you'll enjoy it.

BigRat

Piston parts look kinda like the Sig 556 stuff?

Similar, but different. I used to own a SIG556. In the 556 the piston was inside a "tube".

Bingo, had one, sold it. It was excellent in ways but had some drawbacks I just could'nt get over.

As requested , these are the pics of my SIG516 Gas System and BCG.

On this photo I would like to know if lube should be applied to this area behind what looks to be mini gas rings. They even have gaps that are staggered just like the gas rings on the bolt. Obviously no lube would go on the face of the gas piston in front of those rings.


Rear of the same rod.


The Piston (right) goes inside the Gas Valve (left). Again, you can see those mini gas rings on the Piston. Because of those rings when the Piston and Gas Valve are together it creates a seal that requires a little bit of force to pull apart (just like when removing the Bolt from the Bolt Carrier). This is why I'm thinking there SHOULD be lube on those mini gas ring, but I could be wrong. You can also see carbon fouling on the face of the Piston where it was tested at the factory.


This is the Gas Valve. I did some contrast editing so you folks could see the holes better. Notice how the medium sized hole has some "burning" around it. It's the ONLY one that does. This, to me, is even more evidence that the medium sized hole (not the large hole stated in the users manual) is the NORMAL setting as it is the only hole that shows that burn mark around it from where it was tested at the factory.


When I removed the BCG, I noticed that the color was different from any other BCG I have. It's not black at all, but rather a deep brown-bronze color. You might be able to tell from the photos. Also, after drying the BCG off and before applying my Slip2000 EWL, I noticed the all surfaces of the Bolt Carrier only (not the bolt itself) has a VERY slick feel. The color combined with the "dry, but wet" feel leads me to believe that there is some type of special coating on this Bolt Carrier. Can anyone confirm this?






This is one of the reasons I went with the SIG516. It uses a standard Bolt, unlike the HK416. But unlike the HK416, the SIG516 didn't kill Usama bin Laden. I do know from other users that the gas rings on the Bolt are optional and the rifle will run fine without them. This was confirmed by SIG. I just left them on b/c I didn't feel like taking them off.

SIG Customer Service just called my cell phone and told me I was CORRECT! Apparently, just like I suspected, the pictures WERE INDEED SWITCHED by accident. Humans make mistakes, no big deal. The CS guy got the call from the local SIG516 expert on hand and told him they were switched. It's going to be changed before going to print.

Mystery solved. Vertical 12 and 6 o'clock position is Normal setting. 10 and 4 o'clock position is Adverse. End of story.


I forgot to mention when I was on the phone with SIG Customer Service he said my SIG516 was Gen2 and previous designs are Gen1. Guess I got lucky.

It's strange that SIG doesn't mention this on their website.

It appears the BC has some kinda coating. Cheers on the Slip2K EWL. That stuff is the bomb.

that rifle looks badass how much was it?

$1450 here

How does it shoot?

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Wish I could tell you. I've been too busy remodeling my basement to even leave the house. I should be able to make it to the range within the next two weeks.

Please give us a range report I was looking at getting that same model sig.

Can you give me an idea of what type of info you guys are looking for so I can prepare ahead of time? My range has 50 and 100 yard lanes. I will be using a fixed 4X optic (chevron reticle).

Subscribed.
Any info is better than none. I would like to hear mostly about reliability and any performance issues you might have. Ive just put this same model on layaway. Mine has a "born on date" of June 12, 2012.

So far I can tell you the fit and finish is top notch. I've never had a weapon that had a Cerakote finish until now and I can tell you it looks MUCH better than the standard AR black hardcoat anodize. I'm pretty sure I read somewhere that Cerakote is applied OVER the hardcoat anodized finish. The FDE finish is also on the INSIDE of both the lower and upper receivers as well. I like this as it helps me see any fouling/grime with ease. There is zero play b/t the upper and lower receivers, but this aided by the rubber thingy in the lower that creates tension b/t the two halves. The tension is so tight that I can't remove the rear take-down pin without using the tip if something (like a bullet) it push it through so I can grab the other side. The rifle comes with a "H" weight buffer. I weighed it at exactly 3.75 oz. I'm going to replace it with Spike's Tactical ST-T2 Heavy Buffer that weighs about 4 oz. I know it works b/c I've read reviews on it's use with the SIG516.

Some folks complain that they don't like the length of the rail b/c it's too short. The way I look at it, if the rail were longer (like my 12" DD rail) the piston system would also have to be extended therefore adding more weight to the rifle. Remember, you can't hide the piston control valve under the rail to extend the rail past it like you can the Gas Block on a DI rifle. I'm not a big fan of extending my arm all the way out and grabbing the end of my rail Chris Costa style, even if everyone is doing it now. I might have to go with a vertical grip or the Magpul AFG (Angled Fore-Grip).

The safety lever has a VERY positive "click" when switching from SAFE to FIRE. It's the best I've ever experienced. Even better than my Bravo Company AR. It came with one FDE Magpul P-Mag. It drops freely without issue. The flip-up sights (BUIS) that came with the rifle are just OK. I've seen better (Midwest Ind. are my favorite). They are black metal, but don't feature a button that you press to unlock them. You just pull them up and push them down. There is no positive "click" with these sights where you feel them lock into place. They actually don't lock into place, but rather just stay in place until you push them down or pull them up. They are good enough that I probably won't replace them, after all they are BUIS. It sure beats the hell out of getting that crappy SIG red-dot that used to come with the SIG516. I think enough people complained that SIG is now shipping all current SIG516s with iron sights only. Good move.

Great 516 thread and very nice macro pics, damn sexy 516 in fde you have there, congrats. Would you mind weighing your bolt carrier in lbs and oz? very good job on noticing the documentation correction as well. The new gas block valve design is awesome. A report on 100 or 100+ yard groupings would be great! I was able to take my 516 out to 300m so far.

BTW I just threw in JP reduced power springs bringing the trigger down to a 4.5lb pull just for about 10 bucks from Brownells.

Did you want the weight of just the carrier by itself?

The bolt and carrier together weigh exactly 9.50 ounces. I would like to know how much less my BCG weighs compared to the original LWRC copy. I would also be curious to know if a LWRC BCG would fit AND function in the SIG516. Logic tells me that it would (SIG516 original BCG was an EXACT copy of LWRC BCG), but I don't have the balls nor the money to find out.

How did yours do at 300m?

Bolt carrier by itself if you can. It's true, the bolt carriers has some sort of low-friction coating (which may or may not require lubing, but I lube it anyway). Here is my 516 with 62gr Tula FMJ Russian Steel at 300 meters (first time) with a 4mph wind on a 12" target with a Leupold VX-II 3-9x40 Long Range reticle:

The carrier by itself weighs 7.40 ounces. While I had the bolt out I removed the gas rings. They're not needed. It also smoothed out the cycling a bit. Did you remove your gas rings? What does your carrier weigh?

Great, my SIG 516 'gen 2' bolt carrier also weighs 7.4 oz. I'm one of the owners part of the first wave of the revised carriers with rushed milling marks. Yes, the LWRC nickel-boron coated bolt carrier can be used in the 516, but in the gun politics world it would be considered a compliment to the SIG and blasphemy to LWRC. Unfortunately this topic has been beaten to death in the past and I'm very sure both parties have had the mods lock and remove all topics that had anything to with it (also on the sigforum.com and lwrc forum) so it can be laid to rest and forgotten as it's already been settled.

If it sparks your interest, here are the weight comparisons of bolt carriers:

Standard M16 DI Carrier: 9.35 oz
Stripped LWRC carrier: 9.35 oz
Stripped revised SIG 516 carrier: 7.4 oz

There has been zero reports of any failures with the new style carrier and the lighter weight of the bolt carrier will only result in an increase of the cyclical rate as well as slightly lightening up your rifle weight. I didn't mess with the gas rings at all.

Here are other weight comparisons:

Stock Colt Hard Chrome Carrier: 9.4 oz
JP Enterprises JPBC-3 Stainless Low Mass Carrier: 6.3 oz
Progressive Machine Titanium Carrier: 5.1 oz
Smith Enterprises Aluminum Carrier (discontinued and rare): 3.85 oz

Believe it or not, the 516 carriers have actually evolved in design with more than two versions (you can notice the differences in the picture here):



Question: Are the 'SIG SAUER SIG 516 5.56 NATO' markings printed or engraved into your lower receiver like this?

Mine is engraved and looks exactly like yours...except in FDE of course.

Question: What are the differences b/t the V2 and V3 516 bolt carriers?

Good question. Only thing I can see is that lower small lip towards the rear end/bottom of the bolt - About 4/5ths from the front.

Also, notice that the tail end is completely milled out in the fluted areas.

Additions: 2 quick questions,

Did yours come with the SIG SAUER hard case, and would you mind taking pics of the accessories it was shipped with?

It came in a crappy cardboard box with styrofoam. That's one thing I am kinda disappointed about, but whatever. I always buy a Pelican case for my rifles anyways.

It came with a black sling with swivel attachments on both ends, one P-mag, FDE rubber rail inserts (3), and a cleaning rod and brush....oh and a outdated user manual.

I noticed your trigger group has a bit of shine on it. Is it lube or is there a special coating on it?

Must be lube. It's a standard trigger group. I shot it for the first time today at the range. Details to come....

My 516 is printed and has the V1 carrier.

Which is, of course, easier to wipe down.

Glad they finally did away with the threaded design. Detents work for everyone else, why not Sig. :-P

Rifle looks good!

Range Report:
http://www.ar15.com/forums/t_3_126/579891_.html&page=1&sr=0

Has it been confirmed which way is normal operation for the second gen 516. I just purchased mine and the first time at the range the gun would not cycle the rounds or lock back on the last round. I changed it to the adverse setting, 10-4, and it would cycle fine and lock back. I called CS and they said that the manual is correct and that I needed to clean the gun and give it a go. I'm pretty annoyed since I watched the sig video and the it's dropped in mud and everything and shoots fine.The more I read online I see that a lot of others are having this problem...what gives?

That sucks.  I don't have issues with my 2nd generation 516.  I have my gas setting at the 12 position.

I was the one that actually called Sig and told them the 10-4 is NOT the normal setting as was printed in their online 516 manual. They confirmed I was correct. The 12 o'clock position is the NORMAL setting. If you are having problems on the 12 setting send it back. Mine has been 100% reliable.

I concur. I have a 516 with gen 1 gas block and a 716 with gen 2 gas block and both operate normally with the "dial" straight up and down. The "slightly rotated" position should be high or dirty.

Aaron556 - MANY THANKS for the great pcs and the time you took to make an excellent post!  Your pics and writeup, and everyone's responses have been a great source of info for me, as I have been researching the Sig AR's for some months now and considering upgrading some older uppers to the 516.  Great job!

Other than the piston system and the bolt carrier, is there any proprietary parts on the Sig 516?  Are all other parts standard interchangeable AR15 platform components?

My pleasure. I was so confused in the beginning. First, when I opened the box and noticed the Gen 2 changes. Then, I noticed the pictures in the User Manual (for Gen 1) that came with mine did NOT match what I actually had as far as the piston system. When I called SIG they said just download the updated User Manual from their website that had the Gen 2 changes. When I did that  I noticed SIG had accidentally switched the pictures showing NORMAL and ADVERSE condition settings. It took some convincing, but SIG called me back and admitted they were wrong and I was right and said they would make the changes when the Gen 2 User Manual went to print. I wanted to clear everything up so others didn't have to go through what I did.

Is that you Melvin?

I also own the Browe Combat Optic (BCO). Love it!

Not sure if you noticed, but if you attach the AAC flash hider quick attach adapter on the 10" CQB upper, you can't remove the piston rod without first removing the flash hider first. It won't clear the flash hider. Not sure it this applies to the 16" upper.

The rod can still be removed with the can attached on the 16" model. I have used a Gemtech Halo on my 7" and the parts cannot be removed with that suppressor. Same goes with the AAC 51T flash hider attached. I might try to cut a notch in the 51T so the gas parts can be pulled without taking the flash hider off each time. I haven't really messed with this too much because I'm hoping SIG will have a Gen2 7" platform to replace the Gen1. Once I get a Gen2 system I'll see about modifying parts, etc.

Also, regarding the pics of the bolt carrier posted previously, the variant 3 carrier is full-auto and comes with the SBR uppers.





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How did you not get baffle strikes when using a suppressor on the 7"?

Now that I got the 10" coming, I'm looking for a flash hider I don't have to take off when mounting a suppressor. I thought the Gemtech might work with the two locking "lugs" on the flash hider at the 9 and 3 o'clock positions rather than 12 and 6????

Range report:

OK, so i cleaned the rifle as SIG customer service and the posters on this site have said and I am still disappointed. Here is the range report after cleaning and with the rifle set on normal position

American Eagle AR223 50 grain - Cycles every round but does not lock back on last round...4 rounds in mag

Remington 223 - 55 grain - cycles every round but does not lock back on last round...4 rounds in mag

Fusion 223 - 62 grain - Cycles every round but does lock back on last round..4 rounds in mag

Federal green tip penetrator .556 -62 grain - Cycles every round but it did locks back on last round..4 rounds in mag

Note: If I load the mag with only 4 rounds of any of the ammo brands that I listed it cycles just fine, but if I fill the mag with the full 10 rounds (California), it jams within the 4th or 6th round. I tried this with Magpul pmags and (2) different steel mags.

Here was my test:

Cleaned the rifle ...Magpul mag

American Eagle - 4 rounds
Remington - 4 rounds
Fusion - 4 rounds
Federal - 4 rounds

All rounds cycle but only Federal locks back

Swap mags

American Eagle - 4 rounds
Remington - 4 rounds
Fusion - 4 rounds
Federal - 4 rounds

All rounds cycle but only Federal locks back

Cleaned the rifle ...Magpul mag

American Eagle - 10 rounds
Remington - 10 rounds
Fusion - 10 rounds
Federal - 10 rounds

Either jams, double feeds, or does not cycle with the 4th or 5th round. None of the brands lock back on the last round.

Swap mags

American Eagle - 10 rounds
Remington - 10 rounds
Fusion - 10 rounds
Federal - 10 rounds

Either jams, double feeds, or does not cycle with the 4th or 5th round. None of the brands lock back on the last round.


What gives?....Nothing like the marketing video

This a excellent post, I went by Wally World today I they had a 516 with optics for 890.00.  I'm coious if this is just a fuke (bad apple).

Cheers
Ron

How in the world did they have the 516 for only $890?? Are you sure it was the 516 and NOT the SIG M400?

You need to send it back to SIG and insist they fix it. Also send them the mags you are using. They will send you a prepaid UPS label and make it right. They have excellent customer service. This is the first time I've read a negative review. Every company will produce a lemon it's just a matter of time.

Is your 516 the Gen 1 or Gen 2 version (like mine)?