Question For SIG516 Owners: My SIG516 FDE Gas Block Is Different

[DontCome2MyHouse]

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.

https://lh4.googleusercontent.com/-PFLduJ84DTU/T_3uV4pztmI/AAAAAAAAB-A/tNb0EkpsqxA/s800/%255BUNSET%255D.jpg

Gas setting is at Normal in this pic.
https://lh5.googleusercontent.com/-WELckpcJFsM/T_3urIgPkiI/AAAAAAAAB9Y/dFH1DKTowmE/s800/%255BUNSET%255D.jpg

https://lh6.googleusercontent.com/-Ejxr9XhmD3E/T_3r7oFCcxI/AAAAAAAAB9I/6lEGZLbeiKo/s800/%255BUNSET%255D.jpg

Adverse setting in this pic (valve is at 12 o'clock).
https://lh3.googleusercontent.com/-5YxpVRSY3YU/T_30UbFgn9I/AAAAAAAAB9w/DLepGDlOI3M/s800/SIG516GasSettings.jpg

I think this snapshot from the new "revised valve" owner's manual has the pictures switched incorrectly.
https://lh3.googleusercontent.com/-fx5h9vM_pHc/T_3_NYuwULI/AAAAAAAAB-I/7ltaolxdIY8/s800/Valvesetting.jpg


Notice in this snapshot of the "old" owner's manual it's switched. Valve in the vertical position is Normal setting.
https://lh3.googleusercontent.com/-r7vXRL0IXSM/T_4B04TRZ4I/AAAAAAAAB-Y/txv30tqnMzA/s800/sig_516_gas_settings.jpg

[SpankMonkey]

I really need to look into one of these. Let us know how she runs.

[everyusernametaken]

I like what I'm seeing from the photos. Nice gas block and valve, I like the gas port indicators on the valve knob. Can you post some photos of the entire piston/op rod and BCG? Would really appreciate it.

[GTifosi]

Are you talking about the port hole as seen to the left in the third picture, or the size of the round marks on the setting knob in the 4th picture?

If the former, no idea, just the way they laid it out for whatever reason.
If the latter, meaningless. The dimples are just decoratively sized position indicator marks.

[everyusernametaken]

Are you talking about the port hole as seen to the left in the third picture, or the size of the round marks on the setting knob in the 4th picture?

If the former, no idea, just the way they laid it out for whatever reason.
If the latter, meaningless. The dimples are just decoratively sized position indicator marks.

Why would the indicators on the knob not correspond directly to the three different size gas ports on the valve? I think they show the relative size of the gas port that you have it set to. Otherwise, why would they be different sizes?

OP, take a picture of the side of the valve cylinder with the three gas ports all in a row. That will answer your question about which one is used for "adverse" conditions, where more gas is allowed into the piston.

[GTifosi]

Otherwise, why would they be different sizes?

Artistic free reign, decorative, an identifying feature to differentiate from knock offs.

[DontCome2MyHouse]

Why would the indicators on the knob not correspond directly to the three different size gas ports on the valve? I think they show the relative size of the gas port that you have it set to. Otherwise, why would they be different sizes?

OP, take a picture of the side of the valve cylinder with the three gas ports all in a row. That will answer your question about which one is used for "adverse" conditions, where more gas is allowed into the piston.

The indicators DO correspond directly to the size of the gas holes. I just checked. Pictures to come.

[DontCome2MyHouse]

Should I join and share these findings on the Sig Forum? They might be interested. I heard those guys over there can be vicious though.

[Talon167]

So these are available at LGSs? I've been wanting an FDE one for a while.

Range report, asap! :cool:

[DontCome2MyHouse]

So these are available at LGSs? I've been wanting an FDE one for a while.

Range report, asap! :cool:

I got mine from Palmetto State Armory. I refused to buy the SIG516 until FDE was available. I'm a sucker for FDE. I'm hoping to get to the range soon. I've been very busy finishing my basement.

[DontCome2MyHouse]

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.
https://lh4.googleusercontent.com/-LRQ5uwW3NYI/T_8CQTfnZoI/AAAAAAAACCM/Qh1cry0hxUc/s800/%2525255BUNSET%2525255D.jpg

Rear of the same rod.https://lh5.googleusercontent.com/-l93xmFbT9bY/T_8AYEO1YzI/AAAAAAAACBA/yLLZtIl5YA8/s800/SIG516PistonRod.jpg

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.
https://lh4.googleusercontent.com/-G6fcfN7Du0I/T_8AZk1CjpI/AAAAAAAACB0/X1R1KF0UyC8/s800/SIG516PistonRod5.jpg

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.
https://lh4.googleusercontent.com/-ajWxWdOL7Fg/T_8AZkj-RnI/AAAAAAAACBk/QxIuew_Cano/s800/SIG516PistonRod3.jpg

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?
https://lh5.googleusercontent.com/-322WIuiklf8/T_8AYLENOTI/AAAAAAAACAw/CuyxJ_8u2S8/s800/SIG516BCG1.jpg
https://lh3.googleusercontent.com/-Tnwi2AIjxCQ/T_8AXQLKKuI/AAAAAAAACA8/qsfs2gpG-AM/s800/SIG516BCG3.jpg
https://lh3.googleusercontent.com/-RjGWtE1EKRE/T_8AZG8DMHI/AAAAAAAACBY/1K--ZxExutw/s800/SIG516BCG2.jpg
https://lh5.googleusercontent.com/-oILnSsdOCwQ/T_8AZ-cmZAI/AAAAAAAACBw/voxj1aNCSpA/s800/SIG516BCG4.jpg
https://lh5.googleusercontent.com/-IQj9vJAoTto/T_8AYojnxMI/AAAAAAAACBI/GmiQr_GFqcA/s800/SIG516BCG5.jpg

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:secret:. 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.
https://lh5.googleusercontent.com/-xJwl4HjUsFA/T_8AZkanppI/AAAAAAAACBg/qpKRpuyuleU/s800/SIG516BCG6.jpg

[Arctic1]

I would lube the entire piston and rod. And yes to lubing the part you indicated on the picture. Not exactly the same system, but I lube the entire piston and oprod on my HK416. All gliding surfaces should be lubed.

How much of the oprod/piston goes inside of the valve?

Did you not get an "Operators Manual", that includes a lubrication scheme?

[DontCome2MyHouse]

I would lube the entire piston and rod. And yes to lubing the part you indicated on the picture. Not exactly the same system, but I lube the entire piston and oprod on my HK416. All gliding surfaces should be lubed.

How much of the oprod/piston goes inside of the valve?

Did you not get an "Operators Manual", that includes a lubrication scheme?

Thanks for the info. I will do that then.

Just that small portion on the rod where I put "Should I lube here?" goes inside the valve.

The Operators Manual that came with it was obsolete b/c mine SIG516 came with the "new" piston design (same as the new SIG716). The undated Operators Maunal that was sent to me via PDF from SIG is very vague and doesn't tell specifics on that rod. It just basically says "lube the Piston rod". I want details!!

Does your HK416 have those mini gas rings on the piston rod like mine does? How similar is your system?

[Arctic1]

It sort of similar, but our piston and rod are two separate parts, and the valve/regulator is part of the gas block:

Piston (you can see the gas rings just below the nipple:
http://img10.imageshack.us/img10/2799/pistonh.jpg

Oprod (didn't have a pic on hand):
http://www.hkparts.net/shop/pc/catalog/203648.jpg

Old gas regulator(you can make out the holes on the regulator that mate up with the port on the barrel):
http://img337.imageshack.us/img337/552/regulatorpveiut.jpg
http://img85.imageshack.us/img85/9752/regulatoruteoggassblokk.jpg

New gas regulator:
http://img36.imageshack.us/img36/5383/p3240004.jpg


Ours is not adjustable for use under adverse conditions though, only for suppressed/unsuppressed use.

[DontCome2MyHouse]

Just got off the phone with SIG Customer Service. The guy said the new manual IS correct and that NOW the Normal setting is at the 10 and 4 o'clock position and Adverse is 12 and 6 o'clock.:suicide:

I'm so freakin confused now I can't see straight. He also said the best way to really find out is to shoot it and feel the differences. Looks like I'll be doing a range trip here soon.

[DontCome2MyHouse]

Oh. My. God.


SIG Customer Service just called my cell phone and told me I was CORRECT!:dance3: Apparently, just like I suspected, the pictures WERE INDEED SWITCHED by accident. The CS guys got the call from the local SIG516 expert on hand and told him I was correct and that it needed 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.

[everyusernametaken]

Nice, thanks for the detailed pictures. I'm impressed with this setup, I wasn't aware they were updating it. I had checked out one of the old design 516s at a local shop, it seemed to be pretty well-made,, but yours looks a lot nicer.

Good catch on the misprint. I never really trust what I read until I've done a sanity check. Seen a lot of issues with manufacturer documentation over the years, and learned the hard way years ago to verify everything. Thanks for posting this information.

[Noodles]

Can't say I'm a fan of that rail at all. But other than that, it looks like an interesting alternative to a designed to be piston AR (MR223/LWRC/SR556/etc). It's nice to see a little refinement from Sig and a gas block with plenty of options.

This and the HK are probably the only two I would consider, and for the money and weight, there isn't much in HK's favor other than it's a mil issued weapon so it's known good.

If SIG paints this thing "rainbow" or whatever I'm out though :)

[DontCome2MyHouse]

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.

[DontCome2MyHouse]

Can't say I'm a fan of that rail at all. But other than that, it looks like an interesting alternative to a designed to be piston AR (MR223/LWRC/SR556/etc). It's nice to see a little refinement from Sig and a gas block with plenty of options.

This and the HK are probably the only two I would consider, and for the money and weight, there isn't much in HK's favor other than it's a mil issued weapon so it's known good.

If SIG paints this thing "rainbow" or whatever I'm out though :)

I have a SIG516 10" CQB Upper that is on back-order right now that I ordered in January. I asked SIG why so long and they told me they are back-logged filling military orders for the SIG516. So, the SIG516 is a military issued weapon, but I'm not sure WHICH military placed the order. It might be a foreign military. Considering it's about half the cost of a HK416 and it passed the "over-the-beach test" was enough to sell me. When I read that the HK416 (MR556) weighs about 9 lbs out of the box with NOTHING on it....I said I'll pass.

[everyusernametaken]

I'm interested to know what kind of surface treatment that is on the carrier. I've seen something very similar before in another application, but I can't recall for the life of me what it was. Does SIG specify what it is?

[VIP3R 237]

I'm interested to know what kind of surface treatment that is on the carrier. I've seen something very similar before in another application, but I can't recall for the life of me what it was. Does SIG specify what it is?

I fondled a 516 today and it looks and feels similar to electroless nickel boron but without the goldish metallic shine. I am very curious to the process they are using. I wonder if it's the same treatment Geissele is using on their triggers?

[DontCome2MyHouse]

I'm interested to know what kind of surface treatment that is on the carrier. I've seen something very similar before in another application, but I can't recall for the life of me what it was. Does SIG specify what it is?

I asked the SIG CS rep and he said he didn't know. I looked in the manual, but couldn't find anything. It's not a standard BCG finish that's for sure.

[Tokarev]

Times they are a'changing!

Just six months or a year ago a thread like this would have generated a bunch of responses about how worthless piston guns are and how the Stoner design was never meant to be operated by a push rod.

Nice to see, in my opinion. Pistons might not solve all the world's problems but, as a consumer, it is nice to have options.

[Slvr Surfr]

Times they are a'changing!

Just six months or a year ago a thread like this would have generated a bunch of responses about how worthless piston guns are and how the Stoner design was never meant to be operated by a push rod.

Nice to see, in my opinion. Pistons might not solve all the world's problems but, as a consumer, it is nice to have options.


Sorry, but if I want a piston gun, I'll get one that was built that way from the ground up (ie. Scar,xcr,fal,etc.)

I don't have a lot of confidence in a company that can't tell you which position their own gas regulator should be set on......

YMMV.

[DontCome2MyHouse]

Sorry, but if I want a piston gun, I'll get one that was built that way from the ground up (ie. Scar,xcr,fal,etc.)

I don't have a lot of confidence in a company that can't tell you which position their own gas regulator should be set on......

YMMV.

It was frustrating that's for sure. However, from what I gather, my Gen2 FDE SIG516 is so new, the customer service rep had a difficult time understanding what I was talking about without having the actual rifle in front of him. He could ONLY go by an instruction manual that hadn't even gone to print yet (thank God!). Just b/c the CS rep couldn't tell me (what I already knew) doesn't mean it's a crappy design or company.

The SIG516 "specialist" confirmed my findings to the CS rep and I'm actually impressed by the CS rep admitting he was wrong and that he personally called me to say thanks for catching the mistake in the manual. I wonder how much money I saved SIG by not running a misprint??:thank_you2:

[DontCome2MyHouse]

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.

[Tokarev]

I would like to SIG extend the forend on the 16" model like they've done on the 7" SBR. Note that the gas system itself stays in its current location but the sides and bottom of the rail are extended slightly to cover the gas block.

http://img.photobucket.com/albums/v221/tokarev/SIG516%20Patrol/P1000439.jpg

[DontCome2MyHouse]

Yeah, I've noticed that. I still think I would burn my hand.

[Tokarev]

The extended forend on the 7" model doesn't make contact with the gas block so it doesn't get too hot as long as I don't do a mag dump. Still, there is some convection and heat transfer but the rail doesn't get any hotter than the block itself. Touching a hot gas block is certainly bound to get your attention. If you've brushed up against an A2 front sight post after some full-auto fire you know what I'm talking about.

There's more to the extended forend that just being able to blaze like Chris Costa. The extended rail allows for additional mounting options. This is nice when mounting a flashlight since you can mount the light closer to the muzzle so the light doesn't cast a big shadow. Also, the longer rail allows for mounting slings and lights without giving up space that would otherwise be needed for the support hand.

I also like a longer forend for carrying the rifle in a patrol-type fashion. If you've ever walked a good distance with a little weight on your back, you know it's nice to be able to move your arms around a little once the straps on your ruck start biting into your shoulders and making your arms go to sleep. The old A2 long handguards were good for this since they allowed you to move your support arm to a more comfortable spot while still maintaining the rifle in a ready position.

[DontCome2MyHouse]

The extended forend on the 7" model doesn't make contact with the gas block so it doesn't get too hot as long as I don't do a mag dump. Still, there is some convection and heat transfer but the rail doesn't get any hotter than the block itself. Touching a hot gas block is certainly bound to get your attention. If you've brushed up against an A2 front sight post after some full-auto fire you know what I'm talking about.

There's more to the extended forend that just being able to blaze like Chris Costa. The extended rail allows for additional mounting options. This is nice when mounting a flashlight since you can mount the light closer to the muzzle so the light doesn't cast a big shadow. Also, the longer rail allows for mounting slings and lights without giving up space that would otherwise be needed for the support hand.

I also like a longer forend for carrying the rifle in a patrol-type fashion. If you've ever walked a good distance with a little weight on your back, you know it's nice to be able to move your arms around a little once the straps on your ruck start biting into your shoulders and making your arms go to sleep. The old A2 long handguards were good for this since they allowed you to move your support arm to a more comfortable spot while still maintaining the rifle in a ready position.

That 7" looks real sweet. One of the many reasons I went with the SIG516 was the fact that SIG would actually sell me the 7", 10", or 14.5" SIG516 Uppers. Try doing that with the HK MR556, FN SCAR, or Rurger SR556 if your non-military or non-law enforcement.

[Tokarev]

That 7" looks real sweet. One of the many reasons I went with the SIG516 was the fact that SIG would actually sell me the 7", 10", or 14.5" SIG516 Uppers. Try doing that with the HK MR556, FN SCAR, or Rurger SR556 if your non-military or non-law enforcement.

Good point. The other companies you mention are ignoring a small but growing NFA/SBR market.

[Talon167]

Dontcome2myhouse,

What did it run you, if you don't mind my asking. I went to PSA's site and they're out of stock. I am just wondering if the FDE edition is a premium price compared to the black.

[DontCome2MyHouse]

Dontcome2myhouse,

What did it run you, if you don't mind my asking. I went to PSA's site and they're out of stock. I am just wondering if the FDE edition is a premium price compared to the black.

It was $1450. I don't think there was much of a price difference b/t the black and FDE. I do know if you ordered the FDE you would be getting the Gen2 like mine. If you got the black it could be either Gen1 or Gen2.

[DontCome2MyHouse]

The extended forend on the 7" model doesn't make contact with the gas block so it doesn't get too hot as long as I don't do a mag dump. Still, there is some convection and heat transfer but the rail doesn't get any hotter than the block itself. Touching a hot gas block is certainly bound to get your attention. If you've brushed up against an A2 front sight post after some full-auto fire you know what I'm talking about.

There's more to the extended forend that just being able to blaze like Chris Costa. The extended rail allows for additional mounting options. This is nice when mounting a flashlight since you can mount the light closer to the muzzle so the light doesn't cast a big shadow. Also, the longer rail allows for mounting slings and lights without giving up space that would otherwise be needed for the support hand.

I also like a longer forend for carrying the rifle in a patrol-type fashion. If you've ever walked a good distance with a little weight on your back, you know it's nice to be able to move your arms around a little once the straps on your ruck start biting into your shoulders and making your arms go to sleep. The old A2 long handguards were good for this since they allowed you to move your support arm to a more comfortable spot while still maintaining the rifle in a ready position.

What light would you recommend for this rifle?

[Tokarev]

What light would you recommend for this rifle?

There are a bunch of good choices.

You might want to try something like this:

http://www.primaryarms.com/Streamlight_ProTac_HL_600_Lumen_Tactical_Flashligh_p/stl88040.htm

Attached to the rifle by something like this:

http://www.gearsector.com/browse/category/mounts/flashlight-mounts/surefire-6p-mounts/

[everyusernametaken]

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.

Hate to sound like a broken record, but do you have any pics of the interior of the receivers? :D

Also, is it an accuwedge between the halves that you're referring to? Or is it something SIG made? This is looking like a really nice rifle, I haven't found one at a local shop yet to handle it.

[DontCome2MyHouse]

Hate to sound like a broken record, but do you have any pics of the interior of the receivers? :D

Also, is it an accuwedge between the halves that you're referring to? Or is it something SIG made? This is looking like a really nice rifle, I haven't found one at a local shop yet to handle it.

It's something SIG made that does the same exact job as an accuwedge. It's not removable. I'll get some pictures.

[DontCome2MyHouse]

There are a bunch of good choices.

You might want to try something like this:

http://www.primaryarms.com/Streamlight_ProTac_HL_600_Lumen_Tactical_Flashligh_p/stl88040.htm

Attached to the rifle by something like this:

http://www.gearsector.com/browse/category/mounts/flashlight-mounts/surefire-6p-mounts/

Thanks. Do you like pressure pads (either attached to the rail or vertical grip) with the wire attached to the flashlight tailcap or do you prefer to just activate the light by pressing the tailcap with your finger or thumb?

[Tokarev]

Thanks. Do you like pressure pads (either attached to the rail or vertical grip) with the wire attached to the flashlight tailcap or do you prefer to just activate the light by pressing the tailcap with your finger or thumb?

A pressure pad attached to the top rail is nice if you want something that will allow you to easily activate the light with either hand.

With that said, I'm currently running a Gear Sector light mount and tail switch light on my PWS and my Ruger. I like that the mount/light combo is simple and relatively cheap. I have the light attached to the left side of the forend so I can just push my left thumb forward to turn the light on. Also with the light in this location it is fairly easy to sort of roll my right forearm up over the top of the rail and push the switch with my right thumb when shooting off the support shoulder.

http://img.photobucket.com/albums/v221/tokarev/Ruger%20SR556E/utf-8BSU1HLTIwMTIwNDIwLTAwMTc1LmpwZw.jpg

http://img.photobucket.com/albums/v221/tokarev/PWS%20Mk116/utf-8BSU1HLTIwMTIwNzA2LTAwMjQ5LmpwZw.jpg

[DontCome2MyHouse]

Hate to sound like a broken record, but do you have any pics of the interior of the receivers? :D

Also, is it an accuwedge between the halves that you're referring to? Or is it something SIG made? This is looking like a really nice rifle, I haven't found one at a local shop yet to handle it.

Close-up of the lower. The black thingy in the middle is SIG's version of the Accuwedge, but MUCH better. When you press down on it really hard it springs back up b/c it is spring loaded.
https://lh6.googleusercontent.com/-mFoNXkKQLJ4/UAMSiylDfSI/AAAAAAAACDY/CTPb-I7Juvc/s800/516Lower1.jpg

https://lh3.googleusercontent.com/-NYM6lf8Pfi4/UAMSibRSk3I/AAAAAAAACDM/0lRPwLpx0Bg/s800/516Lower2.jpg

Close-up of the Upper. You can see the part of the piston rod that strikes the Bolt Carrier. It is rounded at the end and fits in the rounded "pocket" of the "carrier key".
https://lh3.googleusercontent.com/-XXpzQKpGB94/UAMSi4h4fAI/AAAAAAAACDU/ceAJRIfg_oQ/s800/516Upper.jpg

[TCBA_Joe]

Seems like Sig put a bunch of tiny little extras into this rifle. Thinking specifically of stuff like the "accuwedge" or the extractor support in the chamber. I'd be interested seeing how well these run hard.

[DontCome2MyHouse]

Seems like Sig put a bunch of tiny little extras into this rifle. Thinking specifically of stuff like the "accuwedge" or the extractor support in the chamber. I'd be interested seeing how well these run hard.

I really don't think SIG's version of the Accuwedge is really necessary. If you have a milspec upper and lower that is properly machined it should have a tight fit. My BCM is very tight.

What is the "fully supported extractor" all about. I read about it in the specs, but I don't understand how it works or the advantage of it.

[Tokarev]

What is the "fully supported extractor" all about. I read about it in the specs, but I don't understand how it works or the advantage of it.


If you look inside the barrel extension at about the 2:00 position you'll see a small button in there. This button rests against the extractor when the bolt is locked into battery and keeps the extractor in contact with the case's extractor groove.

As far as I know, only HK and SIG are using this in their rifles but it seems like a good idea and a simple fix to "extractor bounce." I guess on the other side of the coin, if it did anything to really enhance the M16's reliability other makers would be using it...

[DontCome2MyHouse]

If you look inside the barrel extension at about the 2:00 position you'll see a small button in there. This button rests against the extractor when the bolt is locked into battery and keeps the extractor in contact with the case's extractor groove.

As far as I know, only HK and SIG are using this in their rifles but it seems like a good idea and a simple fix to "extractor bounce." I guess on the other side of the coin, if it did anything to really enhance the M16's reliability other makers would be using it...

Wow. I've never noticed that before. Thanks. If HK is doing it then it MUST be a good idea:rolleyes:

[DontCome2MyHouse]

Seems like Sig put a bunch of tiny little extras into this rifle. Thinking specifically of stuff like the "accuwedge" or the extractor support in the chamber. I'd be interested seeing how well these run hard.

TCBA_Joe,

Have you seen the "Over-The-Beach Test" video? Seems pretty solid.

http://www.youtube.com/watch?v=FQGTts7xyr8

[Tokarev]

Wow. I've never noticed that before. Thanks. If HK is doing it then it MUST be a good idea:rolleyes:

http://img.photobucket.com/albums/v286/montrala/MR223/MR223%20-%206000%20rounds%20later/DSC00079.jpg

Not too surprising that this design would be used in both rifles. That's if the Internet is correct about a former HK engineer going to work for SIG.

[Tokarev]

An interesting PowerPoint on extractor bounce.

http://www.dtic.mil/ndia/2003smallarms/din.ppt

[DontCome2MyHouse]

http://img.photobucket.com/albums/v286/montrala/MR223/MR223%20-%206000%20rounds%20later/DSC00079.jpg

Not too surprising that this design would be used in both rifles. That's if the Internet is correct about a former HK engineer going to work for SIG.

I've noticed that some piston systems feature a spring on the back of the bolt like on the Adams Arms system like this. I've heard of people using this spring on their LWRC.

What does this spring do and what would happen if I put it on my bolt? Would it hurt to try it?

Forgot to ask....how is the wear from your cam pin on your SIG516? What is your opinion on the POF Roller Cam Pin?

https://lh6.googleusercontent.com/-WmaDjZbjdg8/UANI2qxA3EI/AAAAAAAACD0/bM7RYYW0Hzg/s800/lwrc008%2520004.JPG

[everyusernametaken]

Close-up of the lower. The black thingy in the middle is SIG's version of the Accuwedge, but MUCH better. When you press down on it really hard it springs back up b/c it is spring loaded.
https://lh6.googleusercontent.com/-mFoNXkKQLJ4/UAMSiylDfSI/AAAAAAAACDY/CTPb-I7Juvc/s800/516Lower1.jpg

https://lh3.googleusercontent.com/-NYM6lf8Pfi4/UAMSibRSk3I/AAAAAAAACDM/0lRPwLpx0Bg/s800/516Lower2.jpg

Close-up of the Upper. You can see the part of the piston rod that strikes the Bolt Carrier. It is rounded at the end and fits in the rounded "pocket" of the "carrier key".
https://lh3.googleusercontent.com/-XXpzQKpGB94/UAMSi4h4fAI/AAAAAAAACDU/ceAJRIfg_oQ/s800/516Upper.jpg

Thank you very much for all the photos. I'm very impressed by what I'm seeing. The re-design of the gas block and regulator/valve really caught my attention from the start, as it addresses one of my concerns from when I checked out one of the 1st gen models in person earlier this year - the threaded fitting. I know people are using the 1st gen 516 with this threaded fitting successfully without major issues, but I just didn't like the feel of it when taking it apart, knowing the effects of heat and crud on threads like this. I really like this new design, and it appears that SIG is listening and improving.

I'm really digging the FDE cerakote finish too. I was planning for an FDE-themed suppressed piston platform in the near future, and I hadn't even thought of the 516 as an option until seeing this thread and the great photos. This looks like a perfect package for my purposes. I just wonder about availability of an SBR version - anybody know if SIG is making a complete rifle with a short barrel, like 11" or so? I see they sell uppers, but haven't seen complete factory SBR versions of this new 516.

[DontCome2MyHouse]

Thank you very much for all the photos. I'm very impressed by what I'm seeing. The re-design of the gas block and regulator/valve really caught my attention from the start, as it addresses one of my concerns from when I checked out one of the 1st gen models in person earlier this year - the threaded fitting. I know people are using the 1st gen 516 with this threaded fitting successfully without major issues, but I just didn't like the feel of it when taking it apart, knowing the effects of heat and crud on threads like this. I really like this new design, and it appears that SIG is listening and improving.

I'm really digging the FDE cerakote finish too. I was planning for an FDE-themed suppressed piston platform in the near future, and I hadn't even thought of the 516 as an option until seeing this thread and the great photos. This looks like a perfect package for my purposes. I just wonder about availability of an SBR version - anybody know if SIG is making a complete rifle with a short barrel, like 11" or so? I see they sell uppers, but haven't seen complete factory SBR versions of this new 516.

I think you would have better luck buying what I bought, SBR the lower, then buy the 10" CQB Upper. I ordered my 10" CQB in January and was told it would be shipped in September. SIG said they are back logged filling military orders.

[TCBA_Joe]

I've noticed that some piston systems feature a spring on the back of the bolt like on the Adams Arms system like this. I've heard of people using this spring on their LWRC.

What does this spring do and what would happen if I put it on my bolt? Would it hurt to try it?

Forgot to ask....how is the wear from your cam pin on your SIG516? What is your opinion on the POF Roller Cam Pin?

https://lh6.googleusercontent.com/-WmaDjZbjdg8/UANI2qxA3EI/AAAAAAAACD0/bM7RYYW0Hzg/s800/lwrc008%2520004.JPG

In a DI AR the gas not only pushes the carrier rearward, but pushes the bolt forward during unlocking, removing pressure on the lugs.

On a piston AR the bolt is pulled back by the carrier during unlocking putting pressure on the lugs. This pressure can cause broken lugs.

The spring is a fix which pushes the bolt forward during unlocking as the carrier moves rearward.

Hope that makes sense.

[DontCome2MyHouse]

In a DI AR the gas not only pushes the carrier rearward, but pushes the bolt forward during unlocking, removing pressure on the lugs.

On a piston AR the bolt is pulled back by the carrier during unlocking putting pressure on the lugs. This pressure can cause broken lugs.

The spring is a fix which pushes the bolt forward during unlocking as the carrier moves rearward.

Hope that makes sense.

good to hear. Now if I could only find one to buy. I've looked everywhere with no luck.

[everyusernametaken]

I think you would have better luck buying what I bought, SBR the lower, then buy the 10" CQB Upper. I ordered my 10" CQB in January and was told it would be shipped in September. SIG said they are back logged filling military orders.

I really want to go with a factory SBR, so I need a complete rifle. Was that a 10" upper that you ordered in January, or a complete rifle? I haven't been able to find an FDE 10" SBR at all online.

[Merle]

good to hear. Now if I could only find one to buy. I've looked everywhere with no luck.

Try Adams Arms

[DontCome2MyHouse]

I really want to go with a factory SBR, so I need a complete rifle. Was that a 10" upper that you ordered in January, or a complete rifle? I haven't been able to find an FDE 10" SBR at all online.

I only ordered the 10" upper. I asked SIG if they make it in FDE and they said they do not.

You are going to be waiting a very very long time for a complete 10 " CQB rifle. Trust me. It would be quicker to do what I suggested. It would still be a factory SBR, but you're just getting the upper and lower at different times. Call SIG and see what they say.

[everyusernametaken]

I only ordered the 10" upper. I asked SIG if they make it in FDE and they said they do not.

You are going to be waiting a very very long time for a complete 10 " CQB rifle. Trust me. It would be quicker to do what I suggested. It would still be a factory SBR, but you're just getting the upper and lower at different times. Call SIG and see what they say.

For NFA purposes, it wouldn't be a factory SBR, as the lower was registered with a 16" barrel. Adding the 10" upper then requires registering as an SBR, and engraving the lower. I'm trying to avoid that.

[DontCome2MyHouse]

I finally made it out to the range early Saturday morning. The weather was beautiful, 66 F without a cloud in the sky. No wind. Since this was my first time making it to the range this early in the morning I didn't account for the sun being directly behind my target. I was shooting pretty much directly into the sun which was horrible. I don't think this was thought out very well when this place was built. I was using an Eotech EXPS3-0 in FDE and the sun made it very difficult to get a crisp sight picture, but I did the best I could do.

I rested the SIG516 on a crappy rest that I was using for the very first time. I got it because it was cheap. I found that I had to pretty much adjust windage and elevation on the rest after EVERY shot which was really annoying. This thing was just too light to be effective, but it was better than my sandbag. I was using Lake City M855 62gr "green tip" ammo. I shot a total of about 200 rounds without a single malfunction of any kind. The trigger pull was better than average. A little better than my BCM. You can kinda stage the trigger which does help. I only used the NORMAL setting on the gas regulator. Next range trip I may try ADVERSE just to see what it feels like.

I made some slight modifications to my SIG516 prior to shooting it for the first time. I replaced the stock Cam Pin with the POF Roller Cam Pin. I'm happy to report that after 200 rounds there is ZERO wear from Cam Pin gouging on the inside of the upper receiver. The inside of my SIG516 is also Cerakoted in FDE and the finish in that area is perfectly fine. Now, I know Cam Pin gouging is perfectly normal and doesn't effect performance (my BCM has it), but I thought I would try this. The other modification I made was to replace the stock Buffer (3.7oz) with the Spikes Tactical ST-T2 Heavy Buffer (4oz). I use this Buffer on my BCM and I like it. I also removed the gas rings from the bolt. SIG Customer Service told me that they are not needed. The last modification I made was to use the BCMGUNFIGHTER Charging Handle w/ Mod 4 (MEDIUM) Latch.

The following picture was taken after shooting at 50 yards using the Eotech. Like I said previously the sun was in my eyes. Normally, I like to dim the red dot down to the point where I can just barely see it (makes the dot smaller) so that my groupings are tighter. In this case I had to crank up the brightness setting just to see the dot in the sun. I'm sure I could have had tighter groups and when I do I'll be sure to post them. I have read many reports of the SIG516 shooting 1 MOA to sub-MOA @ 100 yards.

I'm sure I'm forgetting something. Feel free to ask questions.



https://lh5.googleusercontent.com/-ze5rR3fQ6PA/UAwUxfrbPgI/AAAAAAAACF4/k3aNFmnPD3s/s800/IMG_20120721_133828.jpg

https://lh5.googleusercontent.com/-JzaXmVQRluI/UAsunM4BQkI/AAAAAAAACFU/55DpxLIT348/s800/%255BUNSET%255D.jpg

https://lh5.googleusercontent.com/-zb08EirOkwM/UAnCPjQFxWI/AAAAAAAACE0/RSTYJ8Pi9qA/s800/SIG516Eotech.jpg

[Merle]

That's awesome grouping for factory defensive ammo. I hope that the Sig516 can change the minds of all the piston and Sig haters on this site. I checked one out the other day at a local gun stores and was pretty impressed by the looks and feel of it. I wouldn't mind having one if I didn't already have my other AR's. Thanks for posting.

[bigboypinoy]

Looks great and shooting great even with the bad lighting. I just sold my Gen1 516 yesterday when I read your thread on AKforum regarding the Gen2. Now to find a Gen2 in CA. My LGS stated possible deliver of 516s in Dec.

The new piston/gas block design is what made me sell the other one. I did call Sig to see if they could retrofit the Gen1 but they stated that I would just have to buy a new upper. Not too many people know about the updated 516 so was happy to sell mine LNIB for $1300 when I got it for $1K.

The new gas block has a new bayo lug as well, have you tested or do you know if this would fit a standard M9/M10 bayonet now? Looking forward to get my hands on one and will probably get the same Eotech, but in black.

http://i163.photobucket.com/albums/t310/kengulo/988dcda9.jpg

[Iraqgunz]

Shooting 3 round groups at 50 yards is in no way a true indicator of accuracy. You need to push it out to 100 yards with 5 shot groups at a minimum, with 10 rounds being better.

[DontCome2MyHouse]

Shooting 3 round groups at 50 yards is in no way a true indicator of accuracy. You need to push it out to 100 yards with 5 shot groups at a minimum, with 10 rounds being better.

I would have if the 100 yard lanes were available. I need to go during the week and not on an overcrowded Saturday.

[DontCome2MyHouse]

I just sold my Gen1 516 yesterday when I read your thread on AKforum regarding the Gen2.

AKForum? I'm not a member of that forum. Strange.:confused:

BTW...I'm not sure if this would fit a standard M9/M10 bayonet. I'm not the bayonet type of guy.

[bigboypinoy]

AKForum? I'm not a member of that forum. Strange.:confused:.


AK47.net was what I meant.

Not you?

http://test.ak47.net/forums/t_3_126/579891_SIG516_FDE_Gen2_Range_Report.html

Aaron556

[DontCome2MyHouse]

AK47.net was what I meant.

Not you?

http://test.ak47.net/forums/t_3_126/579891_SIG516_FDE_Gen2_Range_Report.html

Aaron556

That's me on ARF. I guess it automatically shows up on ak47.net. I never knew it did that.

[Tokarev]

Looks like you're off to a good start. Keep us updated as you progress.

I'd like to make note that your upper receiver should have a bevel behind the cam pin recess. This bevel should remove the spot that otherwise would have been marked by cam pin drag.

[DontCome2MyHouse]

Looks like you're off to a good start. Keep us updated as you progress.

I'd like to make note that your upper receiver should have a bevel behind the cam pin recess. This bevel should remove the spot that otherwise would have been marked by cam pin drag.

A bevel? I didn't know that. Do you have a pic?

[Tokarev]

Actually you can see the bevel in your picture of the upper. Note the slight angle behind the cam pin recess. It can be seen across from the dust cover latch area.

https://lh3.googleusercontent.com/-XXpzQKpGB94/UAMSi4h4fAI/AAAAAAAACDU/ceAJRIfg_oQ/s800/516Upper.jpg

[DontCome2MyHouse]

Actually you can see the bevel in your picture of the upper. Note the slight angle behind the cam pin recess. It can be seen across from the dust cover latch area.

https://lh3.googleusercontent.com/-XXpzQKpGB94/UAMSi4h4fAI/AAAAAAAACDU/ceAJRIfg_oQ/s800/516Upper.jpg

I think I see it. Is this it? Looks like SIG did think of everything. So glad I didn't go with the HK MR556.

https://lh3.googleusercontent.com/-ePaRVsHPQfM/UA3rmGjVusI/AAAAAAAACHA/uVuYtSzI_S8/s800/516Upper.jpg

[Tokarev]

That's it.

LMT also does this. I imagine other makers do as well.





https://lh3.googleusercontent.com/-ePaRVsHPQfM/UA3rmGjVusI/AAAAAAAACHA/uVuYtSzI_S8/s800/516Upper.jpg

[DontCome2MyHouse]

I was reading an article a few days ago in a magazine (can't remember if it was Special Weapons or Tactical Life??), but it had the SIG516 on the cover looking sweet. There was an interview with some guy named Jarrod that was head of the team the designed the SIG516. One of the details he mentioned was that the SIG516 upper was made of a special alloy to give it greater strength. Ever hear of this? An alloy is a mixture of two different metals. I thought the upper was just aluminum?

[DontCome2MyHouse]

Bwahahaha!

http://www.youtube.com/watch?v=BiDNCmOypQU&feature=channel&list=UL

[Redmanfms]

That's awesome grouping for factory defensive ammo. I hope that the Sig516 can change the minds of all the piston and Sig haters on this site. I checked one out the other day at a local gun stores and was pretty impressed by the looks and feel of it. I wouldn't mind having one if I didn't already have my other AR's. Thanks for posting.

I hope Sig un****s itself and once again starts producing quality firearms. Perhaps the 516 line will be a step in the right direction.

BTW, used to love Sig, but that was before Cohen took over.

ETA: And that group is hardly "awesome."

[DontCome2MyHouse]

I hope Sig un****s itself and once again starts producing quality firearms. Perhaps the 516 line will be a step in the right direction.

BTW, used to love Sig, but that was before Cohen took over.

ETA: And that group is hardly "awesome."

It was a big leap for me to go with SIG. No doubt their QC has been in question the past few years with Cohen in charge. But I have read reports that they have addressed those issues and since my 516 was made last month it should be fine. I'll report any issues if they occur.

[Merle]

ETA: And that group is hardly "awesome."
Ok maybe not awesome but pretty effin good for military ammo and considering the conditions that he shot them in.

[texasmarine022003]

I picked up a Gen 2 FDE 516, and it'll fire whatever mix of ammo you throw at it.

[Wulfmann]

Damn you people showing off your new gen 2 stuff. Got me looking and before long got me bidding and before long well
http://i5.photobucket.com/albums/y152/Wulfmann/ARs/516-L.jpg

Then I had to adopt his big brother:
http://i5.photobucket.com/albums/y152/Wulfmann/ARs/716-La.jpg

That also meant i had to buy a couple more Geissele triggers and a couple more EOTechs (555s)

I don't want to get political but this was more about having a few more just in case

Nuff said:big_boss:

Wulfmann

[Njbudman81]

How did the heavy buffer work out?