Good day fellow forumers!  I am in rifle limbo and was hoping to get some assistance from you more advanced Rifle Jedi (I don't even think I'd classify as a padawan).  Is the Sig 516 or 556 worth $200 more than a Stag?  I don't know enough about piston or gas driven systems to know where to begin researching nor do I know much about anything else AR related.  All I know is that I LOVE shooting ARs and I want one and plan to accessorize one.  

Thanks in advance for your help!

Sig 516 and 556 are VERY different.
The 516 is essentially like an AR with a piston kit on it, more standard components, standard manual of arms (if you are used to an AR).

The 556 is basically the internals of an AK-47, wrapped in a modern shell that is more like an ACR than an AR, non-standard components, not the same manual of arms as the 516/AR.

In my opinion, if you can inspect the Sig and make sure it doesn't have any QC issues (Sig quality control has slipped in recent years, making them pretty much industry average, used to be top shelf), either will be a very very good rifle.
I can't say much about Stag, except they seem to be in the middle tier of AR manufacturers, with reviews online that are all over the place, some good, some bad.
If it were my $$$, I would not hesitate to spend an extra $200 to get a 516 over a Stag AR.
The 556 to the Stag or 516 is an apples to oranges comparison, imho.  (I DO own a Sig 556 SWAT and love it, just fyi).
 

That was EXTREMELY helpful!!!  Thanks!!!

No problem, glad I could help.



This is how I break it down, when one is considering a piston gun:



Do you want parts interchangeability with a standard AR?

*This means more aftermarket support, cheaper parts, possible to find parts in a TEOTWAWKI scenario.



If so, then go for an AR with a piston kit, like the Sig516 or Stag, etc....



If not, (maybe you already own an AR and want something different) then a Sig556, ACR, SCAR, etc....might be a good choice!



I did it backwards, I bought a Sig556 because I got a killer price...caught BRD, and now I'm in the process of saving up for a LaRue PredatAR.



 

Well I know that what I absolutely WANT are a good AR (I don't need a top of the line model since I'm new to this part of gun ownership) and a PCC.  I am in love with the Beretta CX4 Storm carbine and the range where I shoot ARs rents out S&W M&Ps.

Funny, I used to own a Beretta Storm carbine in 9mm and I traded it + cash for my Sig556.



Small world.



That beretta storm carbine is hands down, one of the best if not THE best PCC you can buy.  The MP5 is probably the only PCC that I would consider over the Storm.



My little 9mm storm was a tackdriver and would cut ragged holes out of the center of a target at 50yards all day long.
 

FYI- Stag now offers a "plus" option which is all "top tier" tested and materials. For $900 or so bucks, you can get any number of good AR's. I've seen brand new Colt 6920's for under a grand.

If you're into it you can look at building an AR15! There are some decent deals out right now. If you're looking to go from a manufacturer I think a Stag Arms would be a fine first AR-15. Just no longer being new to the AR world if I was to do it again I would put together my own. That being said, I don't know what you're looking for exactly in an AR15, but check out Spikes Tactical. They seem to be the hot new thing around here. BCM is great too...... if you can get any parts as I think they're on back-order. Palmetto State Armory is putting out some good uppers and lowers as well from reports around here. Just to think about! You have to find though what works for YOU in the end.


Daniel Defense seems to put out great ARs as well.

Thanks for the replies!  I am a complete newb to ARs so I would be nervous about building one and I definitely don't want to drop a stack on one knowing nothing about them.  I'd rather get a really good mid-tier brand and add on to it.  I am going to have to sneak whichever one I buy into the house as it is so having a good AR and PCC will be on some real hush-hush ninja shit!!!  LOL!!!  By the way, my boys love shooting AR style 22 cal rifles so I need to figure how to sneak that one in as well.  

Damn!!!  What a problem to have!!!!

theyre easy to build but IMO, unless you have the tools/vises its more expensive for a standard rifle

If it helps you to decide, any 5.56 non-piston AR can shoot 22 rimfire with an inexpensive (around $150) and easy to install conversion kit. You can even buy dedicated rimfire uppers if you wish. The ability to easily convert an AR to rimfire and back again is a nice feature of the AR over the Sig 556 when it comes to inexpensive training and range fun. There is a rimfire version of the Sig 556, called the 522. My 13 year old daughter has one, and it's one of her all-time favorites

Like parabellum_9x19 I own both Sigs and ARs and like them both a lot. Both platforms have their strengths and weaknesses. As far as choosing one over the other I'll simply echo what he said, as I agree with his conclusions.

Here's a Sig 556 Patrol on top, and my daughter's 522 on the bottom:


My other 556 Patrol with an upgraded stock and different optic:

The Magpul CTR stock on this rifle is actually an AR stock with an adapter.

Here are a couple of ARs for balance