Sig 556 want to add folding stock and orange rubber piece?

[Kip42]

I bought a Sig 556 sbr that was made on a pistol.

What is the little orange piece of rubber near the rear buffer tube inside the reciever? Is that needed or can I throw it away?

I have a fixed M4 style stock and want a folder. Want to run a magpul m4 folder. How hard is it to install the ACE folder? Does it bolt on the m4 buffer tube on the sig or do I need to rip the entire unit out? Should I have a gun smith do it?
http://riflestocks.com/catalog/product_ ... cd65825a86

[ilintner]

I bought a Sig 556 sbr that was made on a pistol.

What is the little orange piece of rubber near the rear buffer tube inside the reciever? Is that needed or can I throw it away?

I have a fixed M4 style stock and want a folder. Want to run a magpul m4 folder. How hard is it to install the ACE folder? Does it bolt on the m4 buffer tube on the sig or do I need to rip the entire unit out? Should I have a gun smith do it?
http://riflestocks.com/catalog/product_ ... cd65825a86

The orange piece of rubber is probably one of those " accuwedge" devices to reduce play between the upper and lower...

http://www.midwayusa.com/viewproduct/?p ... ber=698479

If you take it out and there is substantial play or wobble that bugs you then put it back...
As far as the ace stock goes, changing out the stock should be very easy to do... here is a little write up that makes choosing the ace parts that you want easier on the sig 556 forum http://sigarms556.com/viewtopic.php?f=9&t=1659 . No reason to have a smith do that kind of work unless you just simply don't have any tools or desire to do it yourself.

[continuity]

I have no understanding of the Sig 556 stock attachment system. However, I opine that if the Sig's stock attachment system has the same insane and hateful method of retaining the upper's pin detent "bearing", order 3 extra spring/ball kits.

As a note, the design group for this particular element of the AR system were either pissed off slave labor aliens, or offspring of a Century Arms welding monkey, that were looking for payback.

[ilintner]

The detent for the rear push pin is held in place the same way that an AR is so you will definitely want to watch out for that spring when you take things apart, although I haven't had an issue losing mine the dozens of times I have taken it apart and switched the setup around.