View Full Version : Factory Sig 556 Stock for SBR?

August 4, 2009, 04:18 PM
I just purchased a Sig 556 pistol that I'm converting to an SBR. I'd like to use the original factory type stock on the weapon, but I'm not sure what brand that is. I looked at the Sig website & found nothing.
Can someone point me in the right direction as to where I can find that type of stock?

August 9, 2009, 12:06 PM
Don’t know if you’ve already found your solution – but the answer is not that straight forward.

When you say ‘stock’ SIG stock, there are several –

1. Original plastic (Gen I) folding/collapsible – This is considered by many to be the worst of the lot. Cheaply made, the hinge is plastic and long term durability is suspect. Typically can be purchased new on Gun broker for approx $120. You will need to add a standard M4 style collapsible stock (MAGPUL is common) of your chose.
2. ACE manufacturing has a range of top quality machined aluminum parts to convert to any style (left or right hand fold) stock. Again, any standard mil or commercial spec AR baffle tube and corresponding collapsible stock can be used.
3. Original collapsible only – these are nothing more than standard AR M4Gray collapsible, install one of your chose.
4. New style (SIG 55x copy), these are only found on the new style ‘classic’ lowers. If you wish to convert to this style, you will need to purchase a classic and swap out the complete lower – not a cheap conversion.

My 556 Classic SBR with AAC M4-1K: Started life as a 556P, swapped out the lower from a SIG 556 Classic.




August 9, 2009, 12:28 PM
Yeah that's the exact stock I'd like but I'd have to get a whole new receiver?.FML.

August 9, 2009, 01:48 PM
In a word - yes.

www.cogunsales.com sells just the lower, but i think it's like $650.

August 9, 2009, 03:43 PM
That stock is pretty kewl but not $650 cool & having to resubmit the Form 1s. Thanks for you help. I think I'll rock the ACE stock.

August 9, 2009, 04:26 PM
Granted, I don't play around with FTA items anymore, but If i under stand correctly, you are going to take a pistol and but a stock on it, and make it into a SBR. I was under the impression that such pistols had been designed so they would not accept a stock.

August 9, 2009, 05:14 PM
I was under the impression that such pistols had been designed so they would not accept a stock.

Not necessary true – most AR type ‘pistols’ for example can be converted to a SBR by simply changing out the baffle tube.

In the case of the SIG, there is a plug that needs to be removed. Once completed, you can ‘stock’ away.

Did I mention that personally I would not have the ‘pistol’ and the parts necessary for the conversion in the same place until the stamp was in my hands. ;)

To the OP - these are the parts you will need for the ACE -



Took these off after I got my hands on the classic lower.