It's in the 2-20 edition of Atlantic magazine.
Think improvised weapons, with all the manufacturing facilities of a modern society at hand to make them, and thousands of laid-off, retired or just plain super-skilled machinists, welders and fitters.
Look over the photos, and note expecially the simplest, in photo #25. H/T to the Coyote Kid for the linkage.
Strategically, the ability to project explosive projectiles by any means in short-range urban warfare means that it's difficult to hold ground for long. The short-range capabilities of this improvised artillery also means that modern projectile-tracking systems are less effective against it. BTW, those projectile-tracking systems require the holding of ground in the city in combat, see above.
All moral references aside, this is a classic David vs. Goliath story in Syria. A rag-tag but dedicated force with improvised weapons (including slingshots!) against a modern army with modern weapons AND air supremacy. Note that Goliath is losing the war.
There's an "elephant in the room" for the gun-banners, who are, after all, merely another brigade in Obama's army of wannabe sturmtruppen for the wannabe Reich. It's simply this: while the gun-banners are making their desperate push to stop semi-auto rifles and pistols, there are new welders and fitters being trained every day, and thousands of retired/laid off ones whose hands haven't forgotten how to work and join metal.
The smart militia organizer* thinks beyond who has an AR or AK or a truckload of ammo. He thinks of welders and fitters. Yes he does.
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*Obama gets all the headlines as the "Capo Regime" of Community Organizing, but in fact, there are others doing this work for the other side.