Anyone had the stock hand guard milled on the sides between the QD slots.

What weight buffers are folks using with these?

I am using H1 buffers in all of mine (factory standard from Sig) except for one which I have mounted on a Centurion Arms lower that came with an H2 buffer.  All work equally well.

SIG 516 piston uppers, 14.5" barrel, at AIM Surplus $549.95

https://aimsurplus.com/sig-sauer-sig-516-gen-2-short-stroke-gas-piston-223-5-56-ar-upper-receiver-group/

Crap.  Do I need a third?  Wife says she wants the same gun I have...happy wife, happy life right?

These any good? Was considering picking one up but have heard differing things about Sig QC being very hit or miss.

Are they cold hammer forged barrels?

They're a basic mil-spec upper with a piston instead of DI.  They shoot anything and everything you put in them with minimal maintenance and you'll find very few issues with it.  They're heavier than a typical AR but you'd have to put in quite a bit of effort to break it.  I've got two now.

They just plain work.

According to everything I've read, they are CHF and chrome lined.  They are quality rifles.  I've got five (5) of them and no problems, not even a single malfunction, with any of them.  They are built like tanks, which is good and bad.  Good in that you can't hurt one, bad in that they are heavy.  If you're thinking about getting one, I would recommend it based on my experience.

I picked up two of the 14.5" uppers from SIG during a previous sale.  Left one alone, and cut the other to 11.5" for my SBR.  The gas blocks on both are canted so badly that all but one set of BUIS I have run out of windage adjustment before I can get them to zero.  No one wants to work on them due to the pressed on gas blocks,  pressed in pins for the blocks, and propriety barrel nuts.

I like the uppers, but I'm rather disappointed with the QC.

Already sold out!

Glad I passed.  Going with the Caracal 816A2

I REALLY wish I could buy one of their 11.5" uppers for my SBR.  I'd even consider a complete rifle, if I could find one.

you think the Caracal piston upper is ever going to be avail again?  I've given up hope on them.  Even Rainier finally removed them from their web page.  and they were 2x as expensive.

I visited my LGS today to look at a .300blk Virtus.  Didn't buy it, but had an interesting conversation with the sales guy I always deal with.  He is their "AR" expert and the store is a very Sig oriented shop.  He owns several 516s and the store sells a lot of Sig product.  He told me today that Sig is getting ready to release a large number of "refurbished" (i.e.CPO) 516s into the market at a considerable discount.  He knows I am a 516 guy (bought all of mine from him) so he wanted to share that with me, thinking I guess that I might be interested in buying some more.  He thought retail pricing would be around the $1099 mark for a complete CPO 516.  FYI.

Nice, thanks.  Maybe my wife will get the black one she always wanted...

This is why I don’t buy SIG anymore... While they do make some great products they have a long history of abandoning products and dropping support, and you never really know when that will be.

With respect to the 516, it is not dead as of now.  The marketing effort that Sig is currently making with these rifles reflects their original design purpose: i.e. a "416" based piston AR for Mil/LE use.  With the high prices Sig set for the 516, it was never going to be a mass market civilian AR success.  Indeed, as well received as the MCX has been, its price point is likewise going to inhibit success in the civilian market.  The MCX is interesting in that it has turned out to be, albeit with a little tweking from Sig, a really nice rifle that is gaining interest and acceptance from Mil/LE and now is getting civilian interest as well (view Garand Thumb's and Mac from Military Arms Channel's reviews of the MCX Virtus--both very positive).

Sig Sauer USA seems to be getting its act together as it becomes one of the major firearms producers in the world.  Their facilities in NH are world class.  They make a lot of the stuff that goes into their products.  They are gaining new Mil/LE contracts consistently.  But remember that Sig is essentially a business, and like most other businesses, it exists to make money.  They have to identify which products make money and which don't, and adjust accordingly if they want to stay in business over the long run.  There are many brands of AR rifles that once were popular that no longer exist today.  The classic P200 series (220, 226, 229) is a good example of a terrific product that is in absolute danger of disappearing, or at best existing only as a "premium" (i.e. Legion) model at a very high cost.  Why?  Easy, the polymer striker fired pistol owns the pistol market, and will for the foreseeable future.  With its military contract for the P320, it is obvious that Sig is going to make production and continued development of those firearms one of its primary objectives.  There are no more Mil/LE contracts for the P200 series of pistols.  Is that Sig's fault?  Was it S&W and Colt's fault that Glock came along and grabbed the LE pistol market?  I don't think so.

Sig will quit making the 516 when customers stop buying them.  So far that hasn't happened.  Indeed in Europe the 516 is still a part of Sig Germany 2020's civilian catalog offerings.  It is likewise still a part of Sig's LE catalog as well.  I predict the 516 will be available for awhile longer.  You may have to look a little bit harder to find one, but they will still be out there, as will parts and support.

Just curious, since the gun has a "lifetime warranty", is it technically ever in danger of that changing? Will there ever be a time when Sig can say "We don't honor the lifetime warranty on the 516 anymore"?

Well, if you read the actual language of the warranty, which is a "limited lifetime warranty" that applies only to the original purchaser, Sig has the option of repairing, adjusting, or replacing your firearm.  In the case of a long discontinued firearm for which parts no longer exist, Sig would have the option of offering you a replacement with the current "equivalent" firearm that they manufacture.  So, in worse case scenario, Sig would be offering you an MCX Virtus for your non-repairable 516.

I got mine, gas block is solid straight.  fit & finish quality is top notch on my sample of 1.  equal to my Caracal 14.5" piston upper.  I'm pleased.

Your experience is the same as mine has been.  Over a period of several years I have purchased several 516s.  All have been literally "perfect."

So does anyone know where any sig uppers are in stock?

There are several for sale on Gunbroker.  Otherwise, You would have to daily check the Sig parts store website.

I've had three 516s...all of them had a slight cant in the gas blocks...one had a canted barrel nut...nut sure how that happened...

Had two MCXs....one had out of cut on the charging handle channel and the other keyholed after 200rds....

I don't trust Sig's QC anymore unless for .gov ... they seem to put more QC into .gov units than civilian.

Also, the barrels on 516s have not been cold hammer forged for a while now...they switched to nitrided button rifled barrels around late 2014 made by Green Mountain when they released they are making MCXs ... early 516s were CHF... there is a decent chance that these uppers would feature a CHF barrel as they were a contract overrun...

How to tell the 516 barrel is CHF or nitrided? Is there a sort of marking on barrel?

If its nitrided...it will have a black, deep finish...

The early CHF guns were phosphate but they didnt have CHF markings of any kind...there was a transitional period where CHF barrels and the cheapo Green Mountain barrels were phosphated...I believe at that time...they also went to a cheaper 4140 steel through green mountain...

Sad part about SIG is that they do not announce rolling changes at all and many times do not even update literature...

The 516 is dead...MCX is their go to platform now and they have had muuuuch better success with that vs the 516.

In truth, the 516 was a rushed project to try and take away HK416 contracts...which it failed to do.

Sig716 does better than the 516....both commercially and .gov.

The last AM sale that just past is definitely phosphate as of my sample of 1

Pretty sure those 14.5 uppers that they sold were part of a contract overrun and has a chance on being CHF...unfortunately...somewhat hard to tell...

Is the 1:7 twist roll mark on the shoulder by the muzzle brake...or is further down the barrel like a Colt? If I remember correctly...CHF barrels were roll marked similar to Colt...while button rifled barrels including the nitrided versions had a more, precise CNCs lettering.

Roll mark says "5.56 NATO 1/7" and it is about a 1/4" under the muzzle going around the barrel, not straight across like on my old Colt barrels. Wish I could post a pic, but its been years since doing so and I wouldn't even know what website is commonly used these days to host / store them.

Yup..thats the new gen...no CHF...could be chrome lined...you won't know until you take the muzzle device off.

Recent batch of phosphate barrelled uppers from Sig that I handled were definitely chrome lined; pinned and welded 3 of them, figured I'd check the bore while I was there.

Confirmed, my sample of one is chrome lined...

I got mine couple weeks ago. finally have chance to take some pictures
The hand guard gap is big on upper receiver side but kind of even with piston block side so I'll leave it for now
The barrel is chrome lined but not sure if it's CHF

I might try and snug up the rail to the receiver...

I re torqued the barrel nut on my 11.5" cut down 14.5" upper, and gave the gas block a few raps with a dead blow hammer.  It now zeroes the irons with only a few clicks of windage.  I also opened up the holes in a spare gas valve I had (major PITA drilling holes that small in the hardened valve).  It now runs fine both suppressed and unsuppressed.  I may have gone a little larger than I had to, but I'll take the reliability over sifter shooting.

https://aimsurplus.com/sig-sauer-sig-516-gen-2-short-stroke-gas-piston-223-5-56-ar-upper-receiver-group/

$600 though.

Or you could buy it here on the Equipment-Exchange for $750

maybe it's that "have Bill call me" guy?  or of the same ilk... whatever.

I also have two of their 14.5" uppers and they are great. No issues at all and I love the quick and easy cleaning as compared to the filthy DI guns after a range session.

I keep thinking I’d like to get a 14.5 to cut down and sell my 10”. They always sell out while I think about it.

wow, sold out in 1 day.  I wonder how many they had, maybe just 5 units?

No, it's just covid times and Sig has been selling the 516 uppers at a heavily discounted rate.  That ensures that they'll fly off the shelves as fast as people can fill out the billing form.

I've got the P516 10" version and was wondering if the gas valve for it is the same as the one on the longer version (516). Mine is terribly over gassed when suppressed. Looking for a way to turn the gas down another notch from the suppressed setting.

The other valves can fit if they are the same generation. The current are non-thread. If you find a threaded valve it is different.
I have a thread somewhere detailing the differences and my search to make my 10” 516 more liveable as a lefty.

Here you go

What's interesting is that the one that the OP of that thread mentioned he found worked (the 1702058R) takes me to a discontinued gas valve for a completely different rifle. Still hunting and have found two:
https://www.gunpartscorp.com/products/1564340
https://www.cdnnsports.com/ar15-threadless-gas-valve-sig-sauer.html#.XyIt_oh7n9R

I have that CDNN valve. The ports are smaller, which will help. I don't see the smallest port valve anywhere. Not sure about what part that Numrich valve is.

The CDNN valve being 1702325-R? That's the one that the Sig customer service guy said was for the 16" version of the 516. He could not tell me the size of the ports. This is the pix of my gas valve for the P516 (10" version). Thanks. Smaller will be better on my highly over gassed rifle.



If the 1702325-R is not small enough, I found an armorer that would weld them closed and drill a new set of 3 smaller ports. Real PIA but I would really not like to send it back to Sig for a second time. Especially now with 'Rona. I should have the 1702325-R in a few days. It has shipped.

In case anyone wants to know what it looks like to have the entire thing cerakoted in FDE, here's mine.