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SIG 516 Major Issues

196K views 175 replies 95 participants last post by  Dragonware 
#1 ·
Just purchased a SIG516 gen 2 in FDE, and I really want to love this rifle. Problem is that I have fired 300 rounds so far on two separate occasions, and with every magazine there have been issues.

Issues:

1.) Rifle will not cycle the next round
2.) Bolt does not lock back after last round
3.) FTF, FTE

Let me also add that upon receiving the rifle it was thoroughly cleaned and lubed. I checked to make sure that the normal operation setting was engaged (12 o'clock position)

Ammo:

One day I used PMC 55 grain .223, and the next day I used PMC 55 grain 5.56

Customer Service:

After telephoning Sig's CS, I was told that the rifle needed to run in adverse conditions to properly cycle 55 grain ammo. Is this the case? The manual states not to operate in adverse conditions for long periods of time. Is this a case of bad ammo? My friend purchased a Spike's Tactical ST-15 the same day, and his embarrassingly fired off every round no problems.

Any suggestions? Is this just a bad rifle that I should send back to SIG for repair? Does anyone have experience with this level of unreliability?
 
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#4 ·
I also have a 516 gen 2 FDE, and all I really shoot is 55 grain PMC or UMC. I havn't had any problems at all. What kind of mags are you using. Are the rounds all seated properly to the rear when in the mag? If using old mags try to take the spring out of the mag and inspect. Also I only operate in the 12 o'clock position unless suppressed
 
#5 ·
Thats a 1:7 twist barrel on the sig right? Is the 55-grain a tad lighter than Ideal? Either way I doubt if the ammo accounts for your problem. That speaks to projectile balistics not your cycling issue

I too will be watching this thread. I planned to get a 516 soon and have 5.56 Nato 62 and 75 grain federal, hornady and PMC's waiting for it that my colt shoots fine enough.
 
#6 ·
Hey zombie spice,

Im having the same problem with my brand new 516. My thread is right below yours named "New 516 wont cycle". So far I have been advised to clean it and try again. I could only get it to cycle in the adverse setting. I will clean and try again and post back when I have some results. Let me if you find another solution.
 
#9 ·
I Hope this is not a sign of things to come with SIG's CS.

First, I was told to run the gas piston on its adverse setting. A setting reserved for when the weapon is muddy (like the great youtube video we've all seen), or excessively dirty after many rounds without cleaning. The same setting that the manual warns of operating for long periods of time.

Now you were told to clean the rifle and that would solve your problems.

I just wish, and this goes for a lot of gun manufacturers, that they acknowledge that many firearm owners are: intelligent, responsible, and informed. And that they don't dismiss our legitimate concerns with cookie-cutter responses like "Oh you just didn't clean the firearm", "You were using bad ammo", "operator error", blah blah blah.

As I am a total pacifist, and hate confrontation, anyone have any suggestions on how to handle my second call to SIG?
 
#10 ·
If you call them just simply ask if SIG still stands behind their product. If so make them give you a RMA number to get your rifle fixed.

As everyone knows, it hard to build a good reputation but it is easy to ruin one. If the people at SIG are smart they will own up this problem.

Just my two cents.
 
#11 ·
I just ordered a 516 FDE ... I'll be watching this string with interest.
 
#12 ·
I was having the same problem with my new 716 Patrol, and getting the same responses out of Andy at Sig customer service. After three cleanings, three range trips, a new cleaner and lubricant, and 140 rounds of assorted 7.62x51 and .308 cartridges, the rifle appears to be working properly now. It needs more rounds to verify, but I'm cautiously optimistic at this point. I did get an RMA number on my second call, as well. See the thread on the 716 not cycling properly for my story.

Initial quality for SIG seems to be a problem with some new models. Reference the cycling issues on new Mosquitoes a while back, the product advisory on the P238 when first released, and some of the current stories of new P938s going back for new extractors and feed ramp polishing in order to function, along with loose grip screws. This kind of stuff should simply not happen on brand new weapons.

I'll avoid new Sigs for a while, although I just plunked down some money for a good 'ole West German P226.
 
#14 ·
Hey Guys
Just to let you know my experience with SIG. I pought a Sig 556 Swat Patrol. liked it...after about 500 rounds the top rail came loose above the receiver. I called Sig...got a RMA within a couple days. The rifle was returned within aprox a week. It calimed to have the rail fixed...but I sent photos of the rail showing it was still out of line and loose. It also had some finish issues. SIG emailed me back within a couple days saying they would replace the rifle with a new one. I asked if I could upgrade it. They agreed to replace it with a 516 (and a few bucks).

I received a black gen 1 516 within a week. The rifle has had about 700 rounds thru it without any issues. I fire mostly 55 grain ammo...American Eagle, Federal, PMC....I went hog wild and did put some Black Hills Ammo thru it.

I have found the rifle to be a keeper. If you talk with SIG and discuss the documented issues...they will respond...just be sure you document your issues well and photograph any problems. I was going to use the 516 as a trade in on a SCAR 17.....but I liked it so much I kept the 516 and bought the Scar 17 too. There are a couple guys on the FN Forum that have bought the 516 FDE gen 2 and give it good reviews.
The 516 gen 1 and gen 2 both have had good reviews...but like every rifle....there may be some with defects....if that is the case...discuss it with SIG and I think you'll find them decent people to work with. They will help.

Good luck and I hope you'll get your problems solved. They treated me well and professionally.
 
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#15 ·
It's no secret that there are a lot of problems at today's Sig Sauer. This is not the same company that made the world's finest firearms 20 years ago.

Pound on customer service until you get the answer you want.
 
#16 · (Edited)
I didn't get to spend much time on the range but I shoot 140 rounds this morning. I only had tow stovepipes at the very end. No FTF issues.

I used CLP to lube the bolt.

I was shooting American Eagle 55 grain. I tried cheap wolf ammo 62 grain and I had FTF issues.

I going to go back to range next week and I will report back.
 
#17 ·
UPDATE

Just had my third operations test of the SIG516, as well as, my second encounter with SIG's customer service.

Test 3

First mag of 30 rounds 55 grain Federal went off without a hitch, but bolt did not lock back after empty. Next magazine was back to the issue of not cycling next round. After two magazines of the same old FTF and bolt not locking back on empty, I switched the gas setting to adverse conditions, put in a fresh 30 round mag, and angrily rapid fired every round without any issues (including the bolt on empty).

2nd Call To SIG CS

Nothing. The rep just told me to run the gun in adverse conditions on 55 grain ammo. Never acknowledging there is any issue with the firearm whatsoever, and never recommending to send it back to be checked. His advice was so easily given, it was as if this was the design intentions of the gas settings itself. Maybe SIG should have called it "55 grain ammo setting" and not "adverse". Because of Monday's holiday, I could not purchase any higher grain ammo to see if the normal gas setting will cycle properly. Stay posted.

Meanwhile, my friends' (we all purchased AR's together) Spike's Tactical and M&P Sport have been functioning flawlessly round after round.

FML.

Any Recommendations?
 
#18 · (Edited)
Damn sorry to hear that. I was looking around on youtube and this guy had problems with his SIG 716 and he cleaned his bolt and used Remington oil. Perhaps try that?

I have to admit I am ****** my 516 would not load wolf ammo. I am going to try the Remington oil and see what happens.

In regards to SIG CS, point blank and ask them if Sig still stands behind their name. If so demand a RMA get it send back to SIG for repairs.
 
#19 ·
Steer clear of wolf brand ammo, it is known to be underpowered. This is the same for the SIG 716 and Mini 14. All other ammo works fine.
 
#20 ·
On the 516 not cycling, It has more than one setting at the bottom of the piston in front of the gas block. One is for supressed fire,the other is without supressor. And I think there's an adjustment on the un supressed setting. maybe ite was played with before you bought it. try moving it and shooting in every position.
 
#21 ·
516 propriatary barrel nut.

I had to thread a barrel for a muzzle brake on a 516. I found out that the barrel nut was smaller than all other AR15 nuts.I called Sig and was told the wrench is not available. I told this man I could thread his barrel, and I was going to get it done. I measured the diameter of the nut, and made a wrench on my mill, with the digital readout . My first try was 20,5/32 hole at a diameter of 18mm. It was too big. so I jumped down to 16mm,and it was a hair tight. I used a 1/8"file, and in a few mins it fit perfect. I welded a handle to it, and it worked fine. the nut was not all that tight from the factory, and it was a regular right hand thread. I mad an extra one for the gun store I do work for. If I can help anyone out email me. Roger
 
#38 ·
I had to thread a barrel for a muzzle brake on a 516. I found out that the barrel nut was smaller than all other AR15 nuts.I called Sig and was told the wrench is not available. I told this man I could thread his barrel, and I was going to get it done. I measured the diameter of the nut, and made a wrench on my mill, with the digital readout . My first try was 20,5/32 hole at a diameter of 18mm. It was too big. so I jumped down to 16mm,and it was a hair tight. I used a 1/8"file, and in a few mins it fit perfect. I welded a handle to it, and it worked fine. the nut was not all that tight from the factory, and it was a regular right hand thread. I mad an extra one for the gun store I do work for. If I can help anyone out email me. Roger
Tell me more about the barrel nut wrench.
 
#22 ·
Sig 516 Problem.

Hi Zombie, When I got my Sig 516 a couple of months ago, I experienced the exact same problems. After some experimentation and reading a lot of Good (and bad) threads, it's simply a matter of using the Correct Ammo. The 516 is set up and designed for the 5.56 nato round, much hotter than the 223 Ammo. Some of the para-military 223 Ammo like the PMC and especially the Wolf/Tulla/ and others are not loaded to the 5.56 Nato specs. As a result, the lack of adequate pressure does not generate the Cyclic power needed to run the Piston in the 516. Buy some "real" 5.56 Nato Ammo and your Sig will work flawlessly. If the ammo is not advertised specifically as 5.56 Nato, then it's not what the weapon was designed for. Now, there are some ways to cheat (without hurting the 516). As you mentioned, you can run it in the Adverse Mode, but some of the standard 223 still won't work. I've found the Wolf will work about 95% of the time in Adverse setting. Ok for practice, but that's it. The 5.56 Nato is a little pricey, so I just handloaded up a couple of thousand rounds with using regular 223 RP brass with 26grs of Win 748 or H335 Powder, then run flawlessly. Other powders just don't generate enough pressure that is needed. I've also found after firing about a 1,000 rounds of the 5.56 Nato, the 516 works better and better with the Para-Military Ammo (wolf, ect), in the Adverse Mode. But Beware, using the Steel Cased Ammo (wolf, ect) can and will cause a case to get stuck in the chamber and it's a ***** to get out. If your using steel case ammo make "sure" the chamber is clean and Mix up some Brass Ammo with the Steel Case stuff. I shoot like one mag of Steel Case then one mag of Brass Case Ammo. The Brass Case stuff seems to keep the Chamber Clean from the Lacquer on the Steel Case stuff. I don't see any Damage or excessive wear in my 516 using it in the Adverse Mode. As an Aside, most AR15 gas guns will work OK with the regular 223 Ammo, but Sig's 516 Piston Gun does not, unless you run it in Adverse Mode. Hope this Helps. You will lean to love your Sig 516, I sure do. Jack
 
#24 ·
Bombshell!!!

***UPDATE***

Yesterday was set to be the final test before I sent the gun back to SIG. I went to my LGS to buy 62 grain ammo to see if the problem would persist operating under the normal gas setting. While I was there, the shop owner asked me why i "needed" 62 grain ammo, and what my issues were. He them asked me to bring in the 516 to have a look at it. Disassembled it, and took the recoil spring out. He said he would cut about an inch off of the recoil spring to help with cycling. If that doesn't work, it's a cheap part to replace back to factory specs. I took the rifle to the range and shot 300 rounds without issue using 55 grain ammo, and operating under the normal gas setting, a feet I was unable to successfully do in prior tests. WOW! AM I missing something here? Is this SOP for AR maintenance? Just thought I would throw that out for people who are still having trouble with there 516's.

I will call SIG to confirm that this is ok for operation.

TL;DR: My LGS cut an inch off of the recoil spring, and for the first time, the gun cycled flawlessly.
 
#25 ·
I would think that the spring was the length that it was to compensate for Mil-spec ammo and for fatigue. I have never had an issue with ammo, but then again, I always use LC military ammo, since I did buy a mil-spec gun instead of something non-mil.

Also the other thing that I find odd, is that everyone seems to be cleaning and lubing a semi-auto military rifle with clp. You cannot use that for a lube, you have to use grease on the moving action parts. Once you fire the rifle, with clp most of it will burn off in the first couple of shots, with grease it will tend to stick and stay where you put it. I now when we cleaned and lubed our rifles in the service, we never just put oil on the action, it would never work.

Just my .02 , but I think that if you prepared and treated a military rifle like it was designed, you would get the performance that it was designed to give.


Steve
 
#27 ·
I would think that the spring was the length that it was to compensate for Mil-spec ammo and for fatigue. I have never had an issue with ammo, but then again, I always use LC military ammo, since I did buy a mil-spec gun instead of something non-mil.
Good Point!

Also the other thing that I find odd, is that everyone seems to be cleaning and lubing a semi-auto military rifle with clp. You cannot use that for a lube, you have to use grease on the moving action parts. Once you fire the rifle, with clp most of it will burn off in the first couple of shots, with grease it will tend to stick and stay where you put it. I now when we cleaned and lubed our rifles in the service, we never just put oil on the action, it would never work.
Never used anything other than remington gun oil on any of my guns. Remington is not very viscous so I could see how it migh evaporate after a heavy shooting session. Been lucky so far with no malfunctions but I also make sure to wet the bolt and or rails of my guns before shooting.
 
#28 · (Edited)
Just some notes from my testing with a Gen 2 Sig 516 that had bad short stroking problems. Maybe it'll help some folks with the same problem.

Stock with Sig's H Buffer and I assume std carbine spring
LC M855 - Adverse or Regular: Short Stroking
Winchester Frang 55gr - Adverse or Regular: Short Stroking
Federal AE 223 - Adverse or Regular: Short Stroking
Black Hills Blue Box 77Gr - Regular: OK (only 50 rounds tested)

Stock with Carbine Buffer and carbine spring
Same results as above

With VLTOR A5 Tube (rifle spring)
Federal AE with Std. A5 buffer - Adverse or Regular: Severe short stroking
Winchester Frang 55gr with Std. A5 buffer - Adverse or Regular: Severe short stroking
Federal AE with A5 4.5 buffer (-1) - Regular: Short Stroking - Adverse: Light Short Stroking. 2 out of 100 rounds
Winchester Frang 55gr- Same as above
Federal AE with 3.8 A5 buffer (-0) Regular: untested - Adverse: OK
Federal 42gr Frang with 3.8 A5 buffer: Regular: untested - Adverse: OK

We intend to test with the regular setting and 3.8 buffer soon. I'm not sure how the 3.8 buffer would impact the bolt speed or bounce using mk 262 or any heavy weight round.

We run the guns in dynamic positions in dirt, severe dust, sand and above 100 degrees so there is a higher than normal failure rate. Problems in our experience show up particularly in rollover prone especially with the ejection port facing down and low. Many times we did not see the cycling problem in standard short stroking tests but when run hard the problems would reappear.

I hope this info may help any others. As a note we've run several BCM's, LMT's and Spikes' and a SCAR 16s. None of which had any problems with the same ammo. We have not run any other piston AR. All guns running Frog Lube.

In case you're wondering I tend to not like to return things unless I see an actual broken part. Pretty stubborn, sometimes foolishly. This info is just a data point that may or may not help others. It's not meant to be a cure all or exhaustive test. It only shows what our results were in our conditions.
 
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