I got a free 5-pack of "SigTac" 5.56 30rd polymer magazines when I bought my Tavor SAR about 9 years ago. These are Sig Sauer branded polymer 30-rd mags with green Magpul-style followers. Only markings on the relatively slab-sided black magazines are SIG SAUER and 5.56x45

It came in a clear black plastic box. No other part #s or markings.

I lost these for years until I found them in a corner. I could have sworn people said to avoid these magazines for whatever reason.

Does anyone know much about these? When I do a search for Sig 5.56 mags all I see are the PMAGs these days.

I found a review from 2014 https://www.gun-tests.com/uncategorized/ar-15-magazine-testing-price-has-little-to-do-with-quality-4/

that led me to this

https://www.lostcornerguns.com/in-store-items/in-store-magazines-3736/sig-sauer-mag55630blkply-magazine-556mm-30rd-black-polymer-3651183

Thanks. I did more research and it seems Sig used to include these with their 556, like in 2009-2012 (they switched between USGI / PMAGs as well during that time). I can tell they flex a lot when squeezed at the feed lip area. PMAG M3's flex a teeny bit but nothing like these Sig mags

No kidding! Yep those are the same ones I have, except mine are marked "Sig Sauer" on the other side. So these aren't very good to use even though they are made by IMI?

I had to look at my Tavor receipt from 2014. CDNN said it was a 5-pack of MSAR mags (40rd, 30rd, etc.. mix) but what I got was a 5-pack of these 30rd mags.

I have several of these and some different "Sig" mags that came with a Sig 556 and from Sig's website years back.

Was sort of curious about why "Sig" used the AR-180 cut - but thanks for posting these were an IMI product - makes more sense it was a legacy multi-purpose design by someone other than Sig.  

I have an AR-180 and they do fit and work in it although polymer not so retro looking in it.

https://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_ID=1789

Theres 2 verisons I have found so far both are meh. the skinny plainer one is the worse one. The bulkier more tacticool one is ok but there are better options unless you land them cheap or are desperate.