[Bret]

Due to the $300 rebate and a good price, I just purchased a new Sig556.

Now that I'm getting to fondle it some, I really like the design. It's very interesting how the recoil spring pulls the bolt carrier forward instead of pushing it like AR's and AK's do. Unfortunately, the owners manual is lacking. The paper quality is good, but it was obviously written for a different stocked and sighted version than I have. Because of this I have some questions that I'm hoping you can help me with.
1) How do I install the buttstock extension? I see what looks like a screw in the buttstock with an extra wide slot that would hold it in place, but I don't want to assume anything. Why in the world is the screw slot so wide and what should I turn it with?
2) I think that I'm obviously missing something because the front sight post is right in the way of the red dot. The owners manual says that the front sight post should fold down, but it doesn't. My front sight post is fixed with a hood over it. How is this suppose to work?
3) Where on the rail is the best place to mount the red dot?
4) Are there any other setup things that I should ask/know?

 

[elnonio]

1) Correct. Unscrew the screw, pull the extension down until the retaining tabs are cleared. There will be a large spring for the collapsible stock mechanism. It won't jump out with force.

2) The manual was written for the 556 with the AR stock. Apparently those came with the fold down sight. Here, it's a matter of choice whether you want to co-witness or not. Some will argue against, I have yet to form an opinion.

Theoretically though, at your preferred shooting distance and depending on your preferred sight picture when shooting iron (center mass v. 6 o'clock) the red dot will either be above the front post, or right on the tip.

3) In my case, on the 522 with the SIG diopter, I placed the red dot just in front of the diopter with the necessary clearance to allow me to put the protective cap back on.

4) Hard to know what you don't know, know what I mean?!

 

[goo]

Just bought one and had similar post last week. I had to added the extended buttstock and didn't notice screw until forum. I just shot mine Friday for first time and loved it. It ate up cheapest russian ammo, had very little recoil, and killed two pigs at over 100 yards. Nice first day out.

I paid $1425 at gun deal near my house, but have seen everywhere from $1350 to $1999 for new Classic. What did you pay?

 

[Bret]

I bought it for $1378.50 + $96.50 (sales tax) = $1475 out the door. Take away $300 for the rebate and $14.75 in cash back that I'll get from my credit card and I'll be at $1160.25.

 

[tacman605]

Elnonio I also have a 522 and will be taking the diopter rear and hooded front off my 556 and put it on my 522 is this what you did? Some have said it works others say it doesnt.
Who knows.

 

[elnonio]

Elnonio I also have a 522 and will be taking the diopter rear and hooded front off my 556 and put it on my 522 is this what you did? Some have said it works others say it doesnt.
Who knows.

That's what I did. I haven't shot it since I made the swap, but there is no reason it wouldn't work for short range (up to 100 yards). I don't expect that the 200 and 300 settings would work at those distances, for the obvious reason that the power of 22lr would require much more elevation adjustment than 223.

I also expect that I would have to file the front sight down, but that's ok even if I one day were to decide to put it back on the 556, because even on the 556, the front sight was too tall at 100 yards using adequately powered ammo (I ran out of elevation!)

 

[tacman605]

Ok cool will give it a shot when I get home. I bought a set of the original Swiss diopters and a 550 front sight from Colorado Gun expensive but I think will be worth it.
Front sight is on the way rear in about 15 days.

 

[Bret]

I field stripped it today. It was pretty easy.

I do have another question. What keeps the bolt carrier, gas tube, and the inside of the receiver from rusting since they're not finished (other than oil)?

 

[tacman605]

The inside is parkerized or blued whichever they use for a finish that resists corrosion the gas tube is I think aluminum, correct me if I am wrong here guys, which also resists corrosion. They will rust over time and without proper care but would take a long time for it to do that.
If you ever see the phrase mentioned about salt water corrosion tests that is what they are attempting to do is give the finish long term abuse in a short period of time.
Almost forgot to ask any problem with getting the firing pin out? Others have mentioned nightmare stories about getting the pin to come out.
Hey also there is an armorer's manual on the main 556 page that you can download which is pretty good. It is for the original rifles but gives you a good idea of what is going on.

 

[Zeus]

The fact that it's stainless steel helps.

 

[tacman605]

ZEUSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS...Ok gas tube is stainless makes sense.

 

[Bret]

Almost forgot to ask any problem with getting the firing pin out? Others have mentioned nightmare stories about getting the pin to come out.

No problem at all. It dropped right out after I pushed the retaining pin out. Are they having problems getting the firing pin out after the retaining pin is removed or are they having problems removing the retaining pin?

The fact that it's stainless steel helps.

Are the bolt carrier, upper receiver, and gas tube all stainless?

 

[hattaresguy]

Don't oil the piston, it will burn right off. No lube is needed up front, all oil does is burn off and leave deposits.

 

[tacman605]

The problem was with getting the retaining pin out. Either came out easily or could not get it out with a hammer. Bolt and stuff are stainless inside the receiver is what I was talking about being blued/parkarized

 

[cruzie27]

Hmm,.. wierd.