Sig 516 or 556

[SCQTT]

I currently have a Bushmaster AR with typical gas impingement OS. I do not shoot much, but I like the idea of the piston style better. I have a Sig 516 Patrol G2 on layaway at the moment. I mostly have Sig pistols and love the brand so I know I want to move in that direction.

I also see the sig 556, that they say is a variation of the Swiss 550, this confuses me.

If I want the latest and greatest Sig with a Piston operating system what do I get? 516 or 556?

 

[JCR]

From what I understand, the 556 system is more akin to the AK setup with a full length rod and the 516 has a short stroke piston system (LWRC M6, HK 556) system. IMHO, you get a lot of rifle for the price with the 556. As far as latest and greatest, both designs have been around for a while. One benefit of the 556 system is the simplicity. With this, you've just got the full length rod. With the short stroke, you've got 4 or so parts in the piston system (I own an LWRC M6). In saying that, I've put 2000+ rounds through my M6 and never had a problem. No FTEs, and only a handful FTFs due to bad ammo. If you want more info, I'd look into the history of the Sig550.

 

[golddigger14s]

Being an AK lover, I currently have the Sig 556xi "Russian" on order. 7.62X39 with an AK magazine magwell. To me it should be the best of both worlds, AR accuracy (to a degree) with AK ammo, and piston drive.