I'm not familiar with the quality of the components used in the Sig. Lets pretend that "Mil Spec" and the ability to withstand rigorous abuse really does matter.  

Any thoughts?

Sig's previous AR configurations have a poor 'rep' online, for some reason.

I got to play with one recently at a gun show.  Felt/looked OK, but it was a really cursory glance.  From the specs I've seen it appears in line w/ other mil-spec models.  

Comes down to your choice I guess.

To me, Sig is not how it was 20 years ago.  I do not know if the guy who had run Kimber is still there making the big decisions for Sig.  I am happy with my Colt.

Then you need the Colt. From what I gather the BCG in the Sig is a semi auto, Colt comes with a full auto. By the time you replace that your in the same cost range as a Colt.

I have a Colt and have handled the Sig...Sig felt lighter and a tad more flimsy to me. Same price range you can get a PSA M4 (if you can find a complete rifle) same price as the Sig and have a better gun

The Colt is better because it's a Colt.

That makes no sense in a Tech forum.

Both are good rifles the Sig does offer a few more options as for ambidextrous controls but other than that they are both good rifles.  I would choose the Colt based on no special parts and the M400 barrel profile just makes no sense and irritates me when I look at it.

We know the Colt is forced to adhere to materials and QC standards. The SIG is an unknown in this department.

Forced how?  They are not producing these rifles for US mil.

This is an easy one, and I am a Sig AR fan. I own two Sig 516 uppers (and a Sig 556).

The Colt is the gold standard for a high quality, fairly priced rack grade rifle.

The Sig M400, which I am a fan of and would not hesitate to buy (just check my M400 thread postings) is of uncertain composition in several components.

-The barrel steel has not been widely advertised, so we don't know if it is 4140, 4150, 4150 CMV or whatever. While many say it's the same as the Sig 516 (with which my experience has been excellent), it's unclear if even that is true. Sig advertises heavily that the 516 barrel is nitrided, but has been silent as far as I can tell on the M400. The barrel also has Sig's proprietary cut profile, so I think it's hard to tell anything for sure other than what Sig tells us since no one else is using those barrels.
-My Sig 516 BCGs are semi-auto, so I would assume the M400 BCG is as well, but cannot say for sure
-The Colt is individually HP/MP tested. I haven't seen anything about the Sig one way or another.
-The Colt bolt is Carp 158. Once again I do not think Sig publicizes what composition the bolt is.

This isn't to say that I don't like the Sig - I do. I'd still buy one over most brands. But in my opinion, the Colt is more expensive for good reason. And for me, still a bit better value (I own 11 of them).

Gonna have to go with the SIG here, do some heavy research on it, you get more features for less money, it has a pin in the barrel extension to support the extractor during firing, the receivers lock up very tight (uses a system similar to the matched Mega Billet receivers) staked Castle nut, very accurate (for a mil-spec barrel) features QD sling mounts on the lower itself, and even the new Sigs (minus the horrible extractors on the P series) are still very good guns. The FA, SA carrier is no real factor as you are not shooting full auto.

Colt all the way. Colt 6920 is what all the other guys try to compare too.

Why do you believe this matters?

The day, last month, when my buddy bought his new Colt 6920, he left his house to buy a Sig400.  He is a big Sig fan, his carry gun is a 220, and he is very much a "gun guy", well read, sold guns for a living, and is an avid shooter.  When we finally found a Sig at the (lousy with non gun junk) fun show we attended, it was way overpriced.  We did inspect it thoroughly, and it passed inspection, and my impression was that if we found one for the right money, he was getting a good AR.  We did not find one, left the show, and went to a shop where he ended up with his Colt.  He is happy with his purchase, but I know he will get a Sig someday, and I am sure that either weapon will suit his needs just fine.

If the choice was between Colt and Sig for me, I would pick Colt

Had a lot of Sig pistols back in the old days and (1) after they began building them in America.

I have read a lot of complaints about Sig's lack of quality control the last few years or so and given that...I would tend to trust that Colt would be more
likely to sell me a trouble free rifle.

They are certainly under no contractual obligation with regards to their non-Mil production, but it is known that for their "LE" models, they do adhere to those standards for materials, testings and assembly.

A 6920 has absolutely two differences with an M4A1:
Semi-auto firing control group versus a select fire firing control group (plus the extra third hole to accommodate).
1.5in less barrel.

With regards to their LE models, you do receive product that has gone through the same QC standards and built from the same materials and given the same testings/treatments before assembly.
The same cannot be said so easily about the Sig (or any other manufacture since only Colt hold the TDP) or about any of Colt's Sporter or Match models.

I have both.  The Sig M400 compares nicely to the LE6920.  Here's how they stack up.
 
Both have an F marked front sight base.

Both have M4 feed ramps cut before anodizing.

Both have chromed chamber and bores.

Both have equal staking on the gas key and castle nut.

Colt has an M16 bolt carrier.
Sig has an enhanced AR15 bolt carrier.

Colt bolt is MP marked.
Sig bolt is not MP marked although Sig states their supplier MP tests all bolts, whether they are marked or not. *

Colt comes with an H buffer.
Sig comes with a standard carbine buffer.

Colt barrel is MP marked.
Sig barrel is not MP marked and Sig could not state if their barrel is MP tested. *

Colt barrel is HP tested.
Sig states all of their barrels are HP tested, whether or not marked. *

Colt barrel is button rifled.
Sig states their M400 barrel is cold hammer forged chrome moly vanadium meeting mil-spec. *

Colt has a standard mag release.
Sig has an ambi mag release.

Sig has a upper/lower tightening device in the lower, the Colt does not.

Sig has built-in sling point attachments in the lower, the Colt does not.

Sig has an extractor support in the barrel extension, Colt does not.

Sig has 6-position mil-spec diameter buffer tube, Colt has 4-position mil-spec tube.

Both have equally bad single stage triggers.

Out of the box, the Sig had no blemishes or marks and was cosmetically perfect, if that is important to you. The Colt had various nicks and dings from careless assembly, most notably around the trigger guard where the rear pin was installed, but also on the delta ring and on various spots on the upper receiver.

The Sig upper/lower fit is tight. There is no play whatsoever - either in the vertical or horizontal. The pins can be pushed out with your fingers. There is slop in the Colt that can be fixed substantially with an Accuwedge.

Both consistently eject to the 3:45 position with everything from cheap PMC Bronze and UMC ammo to NATO M193 and M855.

I can discern no practical difference in accuracy.

Both have been 100% reliable when using quality ammo.

Sig has a lifetime warranty, Colt as well.

* I spoke to Sig Sauer directly to determine this information. With patience, and insisting on speaking to folks who can answer these questions with authority, they will speak to you about the parts used on their guns – although they will not tell you who makes their components.

I've owned excellent guns from both companies, and have seen crap come from both, too. I would characterize the M400 as a good offering that seems to be put together well. I prize both my Sig and my Colt and at this point have no real preference for either one.

––-

Note, there is no such thing as Mil-Spec "4150 CMV" steel.  Mil-Spec steel is either 4150 (a non-vanadium steel), or it is Chrome Moly Vanadium (which is not 4150 steel).  If 4150 steel has vanadium in it, it is usually written 41V50.  41V50 is not Mil-Spec.
Note, there is no practical reason whatsoever to change the buffer or BCG on the M400.  The M400 and the LE6920 have identical ejection patterns with the same ammunition.  

Here are som BCG comparisons:

Thanks.  Very good info and a fantastic apples to apples comparison with those pictures.

I want a Sig 551A1

Buy the Colt, Sig is a newcomer in the AR world and hasn't proven itself yet.

I have both but with different purposes in mind.  My Sig 400 is the 20" barreled model; my Colt is the LE 6920.  Both have free float handguards.  (Aluminum on the Sig, carbon on the Colt.)  Both will shoot 1/2 inch groups at 100 meters off a bench with Hornady V-Max's over a medium charge of Varget.  (I can't shoot that well every time but the rifles both seem to have the ability.)   Both factory triggers were pretty much military feeling.  The Sig is a little lighter and smoother but not much.  I put a set of JP springs in the Colt and am probably going to put an ALG trigger group in it to smooth it up.  The Sig is going to get a full JP fire control group since it really does seem to have potential as a tack driver.  The Colt is the SHTF gun and the Sig is for varmits off a bipod.  The Sig cost $200 less than the Colt and has more features.  The Colt is a Colt.  It is an easy choice; buy both!

Colt is the standard, do you think Sig makes a rifle above the standard?  Having never handled a Sig rifle I can't say but if they make them like their recent production handguns I would go for the Colt.

I went against the majority here. I looked at at both and couldnt justify the price difference..........and got a nifty soft case thrown in for good measure.
http://i72.photobucket.com/albums/i175/dvdeick/001-4.jpg
http://i72.photobucket.com/albums/i175/dvdeick/003-2.jpg
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I like the LE 6920. It is a quality rifle no doubt. IMHO it is not $200 better than the Sig m400.The fit and finsh was better on the Sig. The accesories on the lower are a big plus,and I am really excited about the free "go bag". It is the nicest soft case I have ever handled.

Good choice.  The M400 will serve as well as any Colt will.

I would get the Colt. They have a very long proven reliable track record. They cost around $1k. Don't let the extra accessories gimmick decide on the Sig for you either.

Nice buy!

If I hadn't just bought/built 2, I would be all over one.

The best deal I could find on a Le6920 with the Magpul furniture was $1097. The Sig was $899. Again,IMO ,there isn't $200 worth of difference, and the "gimmick" go bag was the icing on the cake.
I believe Sig Sauer also has a" very long proven reliable track record".

Why go for the uncertain/unproven rifle when you can get a Colt for a decent price?  I wouldn't touch a Sig rifle or pistol with all the problems I've had in their pistol line, I've sold all my newer Sigs. In the past few years so many manufacturers are trying to duplicate the quality we associate with Colt.  Why not go with the real thing?

This has been some overused bullshit since Colt started selling commercially I'm sure...

Somebody has to buy them and test them...

If everbody thought like you, nobody else would be selling AR's now would they...

I love mine.

weird.. my sig m400 doesn't have white paint on the sig sauer logo or on the caliber.. maybe a different production time? or year made?

 

END THREAD  This is all the info you need




this kind of thinking is dumb. Spikes, BCM, DD all were newcomers in the AR world at one point yet we call consider them just as good as colt now. the Sig has a lot of usefully extras. However based on the above comparisons something like barrel/bolt testing  could be questionable. If you want a as close to mil spec as possible go colt. If you like the other feature of the Sig and can over look that they more than likely batch test their barrels (like many other well known brands) get the SIG.. depending on price of course

I recently bought a 6920 shot the shit out of it and it runs like a dream. few mods and some accessories and it is an amazing rifle. As long as the sig does the same who cares. I like colt for many of reasons, but whatever works for someone is fine just learn how to shoot it and shoot it well.