This is a short overview of this mag. Bottom line - looks like a nice competitor to the APG mags!
I ordered directly from their website because no one had them in stock. They were really swamped so I had to wait *quite a while* for it to arrive... as in 6-8 weeks for delivery. I'm probably more patient than some folks, so if you're a *must have it tomorrow*" person, you need to adjust your expectations when ordering.
Direct link to the manufacturer's page:
ProMag | Saiga
The magazine appears robust. Black polymer with metal feed lips. Polymer feels more grainy than some other mags, really close to a Bulgy waffle mag. I'm no plastic expert so that's all I can say about it. It doesn't seem brittle, so it should be able to take some abuse. Spring seems nice and springy. Hand-feeding the rounds into the mag "just works". All 10 rounds can be inserted with no excessive load on the spring. Mine had just a little bit of mold flashing (trim) that caused the follower to drag when inserting, but after a few cycles it smoothed up.
The magazine locks up tight in the magazine well. Mine does not "drop free" like the factory mag, and behaves just like the Bulgy waffle mags do in most of my 7.62 rifles. You have to physically pull the mag out of the magazine well. You can see on the rear locking lug there is a little bit more meat on the sides that seems to be the point where it rubs against the center support. I could easily file this area with an emory board or small file but for now I don't see the need for any modifications.
On the outside of the mag, the top-most "waffle" pattern contacts the bottom of the receiver. I trimmed off a very, **VERY** thin amount from the top of this waffle to get the magazine to more smoothly engage the magazine release. Out of the box, I had to firmly rock it into the receiver to get the rear lug to engage more smoothly and get that "click" that lets you know it is fully engaged. As previously stated, I believe the extra "meat" on the rear locking lug could be trimmed up to get it to fit, however I chose to trim the sides. By a "very thin amount", were talking about the thickness of a business card. These side waffles appear to also serve as an anti-wobble feature. Not sure about that, however it does give it a nice, solid lock-up. The factory mag I have has about the same thing with its side ribs. The ProMag locks up more firmly, which to me "feels" better for my shooting and reloading style. OPINION - I suspect they made this a bit larger to ensure it fits all batches of the shotguns... I don't know for certain how it fits in older -12s since I have only this one available to me.
The follower sits a bit higher than the factory 5-round mag. I don't have a factory 8-rounder to compare to. It is high enough that the bolt contacts the follower after the last round cycles... JUST LIKE the Yugo magazines! This made it MUCH easier for me to grab the bolt and pull it back to the bolt hold open, and made it faster for me to switch mags. If you need really fast magazine changes, this will be a good thing. Also, JUST LIKE the Yugo magazines, it provides you with that extra indication that the mag is empty.
Since the feed lips are the same as factory, the high follower does not seem to affect feeding or loading at all.
OK here are the pics -
... and here are comparison pics to the factory 5-rounder to show the difference in the follower height
... and finally the "side waffle" rib that contacts the bottom of the receiver - like I said, I only trimmed the thickness of a business card: