I picked up 4 new 17 round mags for my MP9 today. The follower that is on them is different from the 3 that came with my gun. I know they had an update out for the followers, but the only thing I can find on them is the old ones were black and the new ones are gray. All of the magazines I have have gray followers. The ones that came with the gun have a 9 molded into them, the new ones I just bought do not. The followers also come about 1/4" from touching the back of the mag body, where as the ones that came with the gun fill up the whole magazine body. I called S&W and the guy was clueless, no help at all.
Top is the new mag, bottom is the original
The followers in the new mag’s look almost like they are designed for the .40 as the area that the round would sit in is larger than the one in the original mags.
I dont really have a problem with the followers as long as they work, I just know that followers are usually what causes mags to be finicky. There is also usually a reason why followers are re-designed. I can tell that the ones that are in the mags(2nd gen) have a bad tilt problem where as the ones in my original mags(3rd gen) do not have a problem with tilt.
My three 9mm mags purchased in Dec '06 (1st gen I presume) look like the top one in your OP pic and have that gap behind the follower. Even some of my newer black follower mags have that gap. With the gray follower mags, I experience an occasional problem with tilt but only when loading and trying to use the witness holes to count rounds. Still, after close to 10,000 rds through the three mags combined, they still feed properly.
FWIW I’ve never had a stoppage in 40K+ rounds using gray followers regardless of follower generation. IIRC the reason 9mm followers are now gray is because S&W was mistakenly putting black .40 followers in 9mm mags sometimes. This did cause problems.
