Sig516 change handguard possible?

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[ARCHIVED THREAD] - Sig516 change handguard possible?

Posted: 5/10/2016 3:54:45 PM EDT

Love my Sig516 but getting a little tired of the front quad rail. I would like to change it to a tube style but I'm wondering if this is possible. Will any company's handguard fit on this thing or is this a odd ball size that nothing will fit on unless it comes from Sig?

Has anyone changed theirs?

Posted: 5/10/2016 4:51:25 PM EDT

[#1]

Without a lot of gunsmithing on your part, your only other option is the Lancer carbon fiber handguard.

Posted: 5/10/2016 6:52:42 PM EDT

[#2]

Wow, so nothing? Could you expand on that a bit please? Does it have to do with the way the handguard connects to the Sig upper?
What kind of gunsmithing are we talking about here?

Also, I was just looking at the new Sig catalog I downloaded from their website and the pictures look like they have changed their default handguard to a keymod tube kinda looking thing. That was what started making me think that there might be an aftermarket tube that finally fits this thing. Maybe they will start shipping with that new tube and if so maybe they will sell them to owners like me to replace the quad rail.

Posted: 5/10/2016 7:18:09 PM EDT

[#3]

Quote History

Quoted:
Wow, so nothing? Could you expand on that a bit please? Does it have to do with the way the handguard connects to the Sig upper?
What kind of gunsmithing are we talking about here?

Also, I was just looking at the new Sig catalog I downloaded from their website and the pictures look like they have changed their default handguard to a keymod tube kinda looking thing. That was what started making me think that there might be an aftermarket tube that finally fits this thing. Maybe they will start shipping with that new tube and if so maybe they will sell them to owners like me to replace the quad rail.

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Yeah, I tested that keymod handguard... 2.5 years ago and it's still not released. I'm not holding my breath.

Just like pretty much every non-DI ARs, handguards need to be designed around the gun itself and aren't as universal. The 516 uses it's own barrel nut that clears the op-rod properly and the handguard needs clearance around theoprod assembly, gasblock, and bayonet lug.

There was a thread a couple years back where someone modified a Centurion to work with it.

Posted: 5/11/2016 12:04:32 PM EDT

[#4]

You are stuck with the short rail until Sig steps up and makes a better designed system. Or you could pay $300 for an ugly carbon fiber Lancer. Best bet, just sell the Sig and buy something newer. Sig is behind the times

Posted: 5/12/2016 9:36:00 AM EDT

[#5]

Oh well. Have rail covers on there now and it works fine. As I said, gun runs great so I don't think I am inclined to get rid of it.

Thanks for the replies.

Posted: 5/12/2016 10:59:02 AM EDT

[#6]

Quote History

Quoted:
You are stuck with the short rail until Sig steps up and makes a better designed system. Or you could pay $300 for an ugly carbon fiber Lancer. Best bet, just sell the Sig and buy something newer. Sig is behind the times

View Quote

The 516 improvements were interrupted by the MCX development. The MCX was originally developed as a Honey-badger competitor until someone said "hey lets make this thing multi cal" followed by "het we should put this on an AR lower". WHile the 516 runs great, spending further development money on a now-outclassed gun would have been foolish. Same reason the 556XI floundered.

Posted: 5/15/2016 9:06:12 AM EDT

[#7]

I don't really think it needs all that much improvement. As I said, I really like this gun. It shoots great and works flawlessly. Can't ask for more than that really. When I pull the trigger it goes bang, repeatedly and without fail. All the time every time. Second thing is accuracy and it does that too.

Only 2 things I wish I could change about it if I could....

1. I wish I could put a different, lighter, longer, forend like a keymod or tube or something. Just wish I had some options there. That would be nice.
2. I wish I could buy spare parts to keep around.

#2 is not really a problem with the gun and more of a problem with the company. They don't like selling parts by themselves and I am the kind of guy that likes having spare parts for my guns and thse parts are not easy to come by. And since they are unique to this Sig, you just don't find them for sale online.

Other than that I am happy and love my gun.

Posted: 5/15/2016 10:41:56 PM EDT

[#8]

I don't know what the deal is with companies not wanting to sell spare parts. That's why I sold my 516. I still have my M400.

Also why I'm a big fan of Windham Weaponry. Bought their .308 and they have all the spare parts right there on their website to order. Sig could take some advice from customers and make a lot more sales. Their Ceo must be an idiot

Posted: 5/16/2016 7:34:19 AM EDT

[#9]

What spare parts are you looking for? Bolts are standard AR as is the trigger group. Really, the Op-Rod assembly is the only spare wear part that's no universal.

Posted: 5/16/2016 7:46:13 AM EDT

[#10]

Don't forget the bolt carrier

Posted: 5/16/2016 8:32:36 AM EDT

[#11]

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Quoted:
Don't forget the bolt carrier

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I wouldn't worry about it. It's a solid piece with an integral strike key that won't come loose. I've seen carriers with 10s-hundreds of thousands of rounds, catastrophic failures, absolutely abused and never any damage to a carrier.

The carrier will last longer than the rest of the gun.

Posted: 5/24/2016 7:15:06 PM EDT

[#12]

Quote History

Quoted:
Don't forget the bolt carrier

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The sigs piston BCG is hardly proprietary, there are other companies BCG that are compatible.
For example i run an AA Bcg in my 516... the only difference is the sig has a small divot in the strike face the AA lacks, you can add the divot to an AA carrier... i didn't on mine. It may or may not cause alittle booger on the end of the oprod. But it hasnt on mine 30k rounds and counting......

Posted: 5/24/2016 11:51:34 PM EDT

[#13]

So I tried fitting a scar rail extension on the 516 but it was a no-go. I've been waiting for a longer rail besides the Lancer one as well. I'm in love with the lower but not so much the upper. It's confirmed you can put in an LWRC bolt carrier if you need a spare bolt carrier.

Posted: 5/25/2016 10:28:59 AM EDT

[#14]

Good thread about Sig 516
https://www.ar15.com/archive/topic.html?b=3&f=126&t=614480

Posted: 7/12/2016 1:06:49 PM EDT

[#15]

Just realized that more had been written here. Forgot to subscribe to my own topic

Thanks for all the info added. I'm looking into it.

Posted: 8/6/2016 9:41:46 PM EDT

[#16]

Hadn't been in the piston forums in forever as I haven't messed with a piston AR in quite some time. Funny to see someone so many years later run into or comment on something that bugged me. Yeah, that old thread is mine. Had a lot of fun mod'ing my 516. There wasn't much interest back then when I did that but over the past 2 years or so I've got a lot of random questions about it or people wanting one of my barrel but wrenches.

Bigbrakes76

Posted: 8/26/2016 12:37:42 PM EDT

[#17]

Quote History

Quoted:
Hadn't been in the piston forums in forever as I haven't messed with a piston AR in quite some time. Funny to see someone so many years later run into or comment on something that bugged me. Yeah, that old thread is mine. Had a lot of fun mod'ing my 516. There wasn't much interest back then when I did that but over the past 2 years or so I've got a lot of random questions about it or people wanting one of my barrel but wrenches.

Bigbrakes76

View Quote

Your handguard rail mod is still better than the newer handguards SIG has released for the 516's. I'm not sure why they don't get the hint when it comes to a good common sense handguard rail design for it. The newer handguard designs that SIG released are hideous. I ended up picking up a lancer extended hanguard and love it, I can even mount it forward towards the muzzle brake if I needed to cover up most of the barrel. If SIG released a handguard similar to the MCX design for the 516, it would be a big hit.

I was at a cross-roads for the purpose of this rifle because it's originally designated as a patrol rifle, but with a carbine gas piston system it's better off to run it as an SBR. With an extended rail I want to run it in 3-Gun but it's better to have a rifle length gas system for 3 gun for less recoil impulse. Looks like we can conclude that it becomes a SIG 516 SPR build.

Posted: 8/26/2016 2:58:19 PM EDT

[#18]

Quote History

Quoted:
I ended up picking up a lancer extended hanguard and love it, I can even mount it forward towards the muzzle brake if I needed to cover up most of the barrel.

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Wait, are you saying that Lancer makes an aftermarket hand guard for the 516?

Posted: 8/26/2016 4:12:18 PM EDT

[#19]

Yes they do! It's aluminum and mostly carbon fiber!

Posted: 8/26/2016 5:11:16 PM EDT

[#20]

Quote History

Quoted:

Wait, are you saying that Lancer makes an aftermarket hand guard for the 516?

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Quote History

Quoted:

Quoted:
I ended up picking up a lancer extended hanguard and love it, I can even mount it forward towards the muzzle brake if I needed to cover up most of the barrel.

Wait, are you saying that Lancer makes an aftermarket hand guard for the 516?

Yup
http://store.lancer-systems.com/product/lch516-cx-l-replacement-hg-sig-516-ext-length-top-rail/sig-sauer-replacement-handguards

Posted: 8/27/2016 8:27:34 AM EDT

[#21]

Wow, I will definitely check that. Thanks for that.
As far as I know that is the only one. Are there any other companies that we know of that make any?

Posted: 11/22/2016 1:55:36 PM EDT

[#22]

OK dumb question I'm sure but I have to ask ... Has anyone seen this? ...

http://www.midwestindustriesinc.com/HK416-MR556-Products-s/266.htm

Since the HK416/MR556 are similar to a Sig516 I was wondering if possibly this would fit? What do you guys think? Anyone seen this rail before?
I guess the big thing would be if the HK barrel nut is similar enough to the Sig barrel nut or if the MI handguard would fit both nuts.

Dreaming maybe but it never hurts to investigate.

Posted: 11/22/2016 2:00:35 PM EDT

[#23]

Quote History

Quoted:
OK dumb question I'm sure but I have to ask ... Has anyone seen this? ...

http://www.midwestindustriesinc.com/HK416-MR556-Products-s/266.htm

Since the HK416/MR556 are similar to a Sig516 I was wondering if possibly this would fit? What do you guys think? Anyone seen this rail before?
I guess the big thing would be if the HK barrel nut is similar enough to the Sig barrel nut or if the MI handguard would fit both nuts.

Dreaming maybe but it never hurts to investigate.

View Quote

They're not similar in the least.

[ARCHIVED THREAD] - Sig516 change handguard possible?

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