I bought a used, 196 series, mini 14 Ranch last year. I beleive the stock is a Choate, has a fixed pistol grip buttstock. The shop had three 20 round, factory mags in stock. They were new in the original white card board box. The side of the magazine is stamped "restricted law enforcement/government use only". I assume these magazines were manufactured during the AWB, so they're a little old. These three magazine work beautifully in my Mini. They easily snap into position. When I push the magazine release these mags will pretty much fall right out. I've had zero malfunctions.
I just bought a new Ruger factory magazine (20 round) from Midway USA. The first couple times I inserted the magazine into the mag well it was tight...very tight, and a little tough to snap into place. It was even harder to remove the magazine. I've since inserted and removed the magazine about 30 times. It's easier to insert, still a pain to get out. This new mag is a very tight fit, where as the three older mags actually have a little bit of wiggle room.
Is this a common problem re: newer mags in an older mini? Did I get a factory mag that was a tad out of spec?