From American Rifleman and The Firearms Blog:
...The Sig 516 is the new AR. Here's a picture for you, but don't tell anyone because it doesn't exist.It had been previously announced (see the firearms blog post above) that they would be producing select fire versions, it wasn't clear that they'd be selling complete civilian legal rifles. Now the NRA is unofficially saying they've confirmed it, with a December order date.
Since we're talking about a new gun, here's what you need to know:
1. It's piston operated and has an adjustable gas regulator similar to the Ruger 556.
2. It has an ambidextrous safety.
3. Comes with Yankee Hill folding rear and front sights.
4. It's an AR.
Looks like they're following the SR-556 mold, in adding premium parts to commodity forgings etc... I see at the least flip down front and rear sights (looks like Sampson, or Yankee Hill. NRA says Yankee Hill, but I can't find confirmation) , a decent rail system, ambidextrous safety, an ergo-grip with plug, a Crane SOPMOD clone stock, and Magpul mags.
Given the relative market failure of their home designed piston 5.5.6 rifle entry (they've sold as many as they've put together, but compared to AR's...) I wonder if this is them throwing in the towel on the SG-556... Of course, they actually share many parts and pieces, so maybe they'll keep them both going.
Better pics here at the M4 forums: http://m4carbine.net/showthread.php?t=37970
In the promo poster on M4carbine you can see an ambi mag release as well, and looking closer, the sights may be from Troy, contrary to the NRA report. I think the rails are (or at least licensed), and they may have sourced or licensed both from the same. Of course they may not have, just to avoid being too close to the SR-556.
Oh and the firearms blog just today posted that Stag Arms is popping out a piston AR as well.
Not much detail yet, but it seems primarily notable in that the list price is $1185, only a few dollars more than their non piston models of equivalent configuration; and several hundred dollars below the list price of every other piston AR I know of.