In a somewhat rare posting for me that is outside of the sales pages, I've decided to pass along 1st hand information regarding the AC Unity AR mags. Not that many good online reviews that are trustworthy specific to these exact mags. I love the Magpul 40's but they currently only come in black and non-window. I really want a coyote with window but settled trying these ACU based on attractive price and availability. I left one loaded with 40 rounds of LC 5.56 for 2+ months. I recently checked it for periodic magwell fitment and sure enough, the dreaded feed lip spreading had occurred by a good amount. It wouldn't insert into several in-spec lowers. If I absolutely made it happen with great force, they would eventually seat but would be rock solid fitment. This to me is a no-go for any serious consideration of use or storage outside of range mag dumps and dirt shooting. Your mileage may vary.

Note: I also have the ACU G19/17 mags which I've left loaded without issue so far. Fully loaded and sitting for 6+ months now. So there's also that.

Good info! Thanks for the review.