Sig 556 pistol to sbr build

**forby** · October 7th, 2012, 08:31 AM

Well here it is.......

Started as a Sig 556 pistol. I did the SBR thing(copy of paperwork in hollow of grip).

Nordic Components collapsable stock intended for AR. The safety gets in the way of the stock rods, so I filed it down. I'm exploring an angled safety from Kreb Custom that also has to be altered to clear the stock.

I am also considering milling down the wire rod portion of the stock to allow for clearance.

The bolt hold open will also not function with the stock collapsed.That's not a concern as I don't intend on emptying a mag in the closed position.

Any thoughts?

I want this firearm to be as compact as possible, so I didn't go for the side folding concept. I would like to make it lighter in front, unfortunately the plastic front stock option doesn't have a place to mount a flashlight!!!!

**Kramer** · October 7th, 2012, 09:35 AM

Nice, I was going to make one using an ACE side folding stock.

**forby** · October 7th, 2012, 05:46 PM

Originally Posted by Kramer

Nice, I was going to make one using an ACE side folding stock.

I actually bought the Ace folding mechanism.... It worked well, but was really clunky looking- big and square. It worked well, but looked like a 5 gallon gas can on a Lotus Elise!!!!

Also, it was WAY too thick when folded.

**mythaeus** · October 9th, 2012, 11:45 AM

Not bad! Thanks for sharing. I'm not so keen on not being able to fire the gun when the stock is collapsed though. I can see situations where that is useful, such as high-pressured situations where you don't even have a single second to extend your stock. Still, that's highly unlikely.

I got the P556 for this exact reason, but living in Philly it's not going to be possible until I get my own LLC (probably late next year). I have Samson rail on mine right now, my heart is set on a UBR stock.

Al

**forby** · October 10th, 2012, 06:18 AM

Originally Posted by mythaeus

Not bad! Thanks for sharing. I'm not so keen on not being able to fire the gun when the stock is collapsed though. I can see situations where that is useful, such as high-pressured situations where you don't even have a single second to extend your stock. Still, that's highly unlikely.
Al

I mostly agree. Only in the confined space of a car, may it be an issue. Once I get the new safety, I'll be golden. Also, the stock extends easily without control manipulation. I can grab the gun by the butt plate and pull it from it's stored location and it will open.

Work in progress.

**steviesterno** · October 10th, 2012, 06:41 AM

I really like it, and might "borrow" the design for my next build. I love a collapsing stock, but I know you can't do it with the buffer system on an AR platform...

As far as a lighter front, couldn't you just get the plastic forend and add a few pieces of Magpul light rail (Sold as their light kit) by either drilling and tapping mounting holes or using epoxy? This should give you the rail wherever you want it, plus lighten up the front a bit.