M&P9 Mag Differences w/Pics

[Tornado_Racing]

Just got a couple of new mags and thought I would post pics of the differences in tubes, followers, springs, and bases. All in all I have 2 different type of tubes, 2 different type of followers, 2 different type of base pads and 3 different type of springs. The Gen2 mag came with my M&P (purchased 8 months ago), the Gen3 mag was purchased shortly after, and the Gen4 just arrived.

As a side note only my HD mags stays loaded and all others I own are unloaded (including these). My M&P9 has roughly 500 rounds through it so these parts are far from being worn out. I do not have info on the Gen1 mag other than it had a black follower.

From Left to Right:
Gen4
Flat Color Tube
#9 Grey Follower
Square Hole Base Pad
Longer Black Spring

Gen3
Flat Color Tube
#9 Grey Follower
Round Hole Base Pad
Black Medium Spring

Gen2
Glossy Color Tube
Grey Follower
Round Hole Base Pad
Silver Short Spring

http://img291.imageshack.us/img291/2456/dscf3658i.jpg
http://img862.imageshack.us/img862/6195/dscf3662.jpg
http://img714.imageshack.us/img714/3835/dscf3665o.jpg

Same as above but all 3 mags stripped down

http://img543.imageshack.us/img543/6838/dscf3667.jpg
http://img707.imageshack.us/img707/562/dscf3674o.jpg
http://img685.imageshack.us/img685/1611/dscf3677y.jpg
http://img190.imageshack.us/img190/788/dscf3671x.jpg

Mag springs with Arrendondo Extra Power Spring
http://img860.imageshack.us/img860/9452/dscf3680m.jpg

One thing I did notice is the new S&W longer mag springs will lock the slide back while using the Arrendondo Base Pads. The other 2 stock springs will not. With the Arrendondo spring I only load 20 rounds as 21 is just too stiff. On top of that it puts alot of pressure on the slide as the rounds do not compress very much. With the new longer S&W spring I can load 22 rounds and the slide still locks, kinda best of both worlds.

[TriumphRat675]

Cool. Thanks for posting that up. Interesting they switched to a square-hole base pad.

If anyone knows off the top of their head whether or not the compact magazines have made a similar switch I would appreciate knowing that as well.

[Magsz]

Im wondering the same.

I have 35 M&P magazines and due to the fact that the new baseplates blow donkey nards im thinking i might have to go out and splurge on a bunch of compact basepads and retaining plates.

The new baseplates were completely unnecessary and quite frankly, they suck...hard.

Im not sure what Smith was thinking on this one.

[GLOCKMASTER]

Im wondering the same.

The new baseplates were completely unnecessary and quite frankly, they suck...hard.

Im not sure what Smith was thinking on this one.

It is my understanding it was to fix an issue of base pads coming off the mag tube while the magazine was being inserted into the pistol during loading/reloading.

[Magsz]

It is my understanding it was to fix an issue of base pads coming off the mag tube while the magazine was being inserted into the pistol during loading/reloading.

Any thoughts on that?

Ive never had a basepad come off and people always ask me why im reloading like im trying to punch through the moon.

[GLOCKMASTER]

Any thoughts on that?

Ive never had a basepad come off and people always ask me why im reloading like im trying to punch through the moon.

I have seen it happen on several occasions and I have been able to recreate the failure on demand. I'm by no means an engineer however, I suspect it was a combination of a somewhat weak spring in combination with the style of base plate and pad. With this combination, the lack of downward tension on the base plate would allow the base pad to slip off during the mag insertion. This is just a guess cause I haven't been able to get a straight answer from an engineer at S&W.

[TriumphRat675]

That would be my guess as well. I have heard of it happening.

Like I said I use full size mags with compact base pads. I haven't had a basepad fly off yet, but I have had them shift forward and have to be reseated. The compact basepads on the full size mags are a step forward in convenience but do not look as securely held as the regular (pre-square hole) basepads.

[Tornado_Racing]

Here is a neat and easy mod to keep the base plates from sliding off during hard/slam reloads. This was the main reason S&W redesigned the base pads (to a weaker design IMHO)

I used an 8-32 buttonhead screw and Drilled/Tapped the spring plate where the catch notch is located. I had to cut down the 8-32 screw to 1/4" in length. The longer screw was hitting the follower on a loaded mag. I then drilled a blind hole in the 10-8 base plate so the screw would sit flush. I tried using a flathead screw but the threads were weak at the base of the countersink. After that I used a sharpee to color the aluminum, re-assembled the mag, and applied a tick of blue thread lock to the 8-32 screw.

This mod can be done using the stock plastic base plates but I would not recommend drilling the blind hole. There just is not enough material as the 10-8 plates are thicker.

Before Drilling, Tapping, and Cutting
http://img41.imageshack.us/img41/3537/dscf3683c.jpg

After Drilling, Tapping, and Cutting
http://img861.imageshack.us/img861/9449/dscf3686.jpg

Assembled Mags
http://img703.imageshack.us/img703/7892/dscf3689.jpg
http://img339.imageshack.us/img339/7126/dscf3692f.jpg

[BCmJUnKie]

I know its titled 9mm mags, but there are differences in .40 also. The mags that came with mine are pieces of shit. The followers tilt so bad its almost impossible to load 4th 5th and 6th rounds, that transfers into feeding also. The MATTE finish is the good one. The glossy are the garbage ones. Malfunctioning magazines are NO use to me. I dont tolerate them
http://i1087.photobucket.com/albums/j468/Danger131/DSCF1848.jpg
http://i1087.photobucket.com/albums/j468/Danger131/DSCF1843.jpg
http://i1087.photobucket.com/albums/j468/Danger131/DSCF1847.jpg

[Tornado_Racing]

I know its titled 9mm mags, but there are differences in .40 also. The mags that came with mine are pieces of shit. The followers tilt so bad its almost impossible to load 4th 5th and 6th rounds, that transfers into feeding also. The MATTE finish is the good one. The glossy are the garbage ones. Malfunctioning magazines are NO use to me. I dont tolerate them
http://i1087.photobucket.com/albums/j468/Danger131/DSCF1848.jpg
http://i1087.photobucket.com/albums/j468/Danger131/DSCF1843.jpg
http://i1087.photobucket.com/albums/j468/Danger131/DSCF1847.jpg

WOW...........did you use the "holy one" for target practice?

[BCmJUnKie]

WOW...........did you use the "holy one" for target practice?

After the 3rd time cleaning it and it still failed I just threw it down range and lit it up. Wit my rifle though. I was pretty mad.

[BrianS]

The new baseplates were completely unnecessary and quite frankly, they suck...hard.

Im not sure what Smith was thinking on this one.

Why are the new ones bad? Just less material between the square retaining plate hole and the edge of the baseplate for wear and tear purposes or what?

[Tornado_Racing]

Why are the new ones bad? Just less material between the square retaining plate hole and the edge of the baseplate for wear and tear purposes or what?

New Design M&P Base Pad Issues (http://gunnuts.net/2010/12/06/mp-magazine-basepad-issues/)

[Tornado_Racing]

Okay, I just measured the springs.

Gen2 .048" O.D. 5.5" Length
Gen3 .049" O.D. 5.75" Length
Gen4 .050" O.D. 6.25" Length
Arrendondo .049" O.D. 7.0" Length

From Left to right:
Gen4 Brand new
Gen4 22 round loaded for 24 hours and still locked the slide back on TF 140mm Extension
Gen3 8-10 reloads or roughly 150 rounds
Gen2 8-10 reloads or roughly 150 rounds
http://img12.imageshack.us/img12/3396/dscf3695n.jpg

[cgcorrea]

A little off topic, but does anybody know if the M&P 45 mags have different generations like this?

[tpdavis89]

New Design M&P Base Pad Issues (http://gunnuts.net/2010/12/06/mp-magazine-basepad-issues/)

Thanks for the link TR.

Certainly something to watch.

[Robb Jensen]

I was shown those new M&P (Gen 4) locking bases at the M&P Pistol armorers class a few weeks back.

I've also never had a M&P base come off either. However I will note that I use www.SpeedShooterSpecialties.com extra power extra long mag springs in my M&P9 17 round 9mm mags and my mags with Arrendondo extensions. My M&P40 mags have stock springs except for the ones with Arrendondo extension which I have the SpeedShooterSpecialties springs in them.

[spr1]

I believe my recent production Gen 3 mags have the latest springs in them but with the old base plates.
I replaced all of my base plates with either 10-8 Aluminum ones or competition oriented extensions.
I can't stand how far the stock base plates stick out on the front side. They make the mag sit in your hand at a bad angle for reloading.

[Tornado_Racing]

I believe my recent production Gen 3 mags have the latest springs in them but with the old base plates.
I replaced all of my base plates with either 10-8 Aluminum ones or competition oriented extensions.
I can't stand how far the stock base plates stick out on the front side. They make the mag sit in your hand at a bad angle for reloading.

Any easy way to check your springs is to put em up against a ruler. Will your springs lock the slide while using a 140mm mag extension?

[spr1]

Mine were .050" wire and around 6.5" long.

[steve126a]

Interesting post. Never paid that much attention to what generation mags I have. I'll have to take a look at them and see which versions I have. Thanks for the info!