40 mags with TF pads & 20 rds. won't drop free

[OPENB]

I've got 6 mags with Taylor Freelance +5 basepads and the stock springs. They hold 20 rounds and are reloadable. But, none of them will drop free when loaded. When the rounds in them go down, they will drop free, usually, but I did have one stick last night with around 5 still in it. I have the 9mm mags with the same bases, and they drop just fine. Has anyone else had their 40 mags with the TF bases swell like this? If so, any fixes? Feels like I'm using the old 1st gen Glock mags.

[partyboy424]

The TF mags aren't designed to be 20 rounds reloadable. I'm currently working on a fix for this with a friend who has a machine shop. You must be slamming the mags in with quite a bit of force to get them reloadable with the slide down? I'm also thinking you haven't trimmed to much off of the followers? If the followers aren't trimmed enough, shoving in that 20th round will cause the mag to swell big time which will cause your problem. For me, to make 20 rounds reloadable, I had to mill out over 80% of the thickness on the base of the basepad (which will absolutely lead to the extension breaking, I just wanted to see how much it would take) and I still had to butcher a follower to keep it reloadable and keep the mag from swelling up.

Hopefully in the coming weeks I'll have a fix for this, wether it's a new extension design, follower design, or creative trimming.

Edit: just realized that you said you had the "stock" springs. If you haven't trimmed the follower, that should get rid of the swelling. Do you have issues with the slide locking back after the last shot?

Edited December 11, 2012 by partyboy424

[RWF]

isn't the +5 for a 9 and its plus 3 for 40?

[partyboy424]

No it's plus 5 for 40, and plus 7 or 8 for 9 i believe. That's the 140mm extension. I haven't messed with the 170mm pads at all, I won't be making an open M&P for a while so I have no real use for the 170's. Also, I've been having a problem with the metal tabs on the back that hold the extension on either not sitting flush or bending. So, I'm trying to make strong ones of those as well. If the basepad slides forward even a little bit due to that metal piece bending back, you'll get 1 or 2 shots off before the bullet/follower hangs up at the bottom of the mag and won't feed.

[OPENB]

It's +5 in 40, +6 in 9mm, same 140 base pad. I don't slam them in too hard, about the same as I did for a full STI mag. My 9mm mags with 23 in them drop free just fine. The 9 mags have vertical ribs I think that make the mag more rigid. I took my SSS magwell off & tried the 20rd mags & they dropped free, so it must have something to do with the mag well. Will look further. I have no problem with the slide on the last shot. The factory springs seem plenty strong. I do need to trim the followers, they hang up at the 17th round.

Edited December 12, 2012 by OPENB

[Fried Chicken Blowout]

I have the same issue with mine. It's hit and miss with the outside temp it seems. Here in the house it's fine and they drop free. I ground down one of my followers tonight to get 20 rounds reloadable. The slight reciprocating is tight with the 20th round pressed under the slide. I might just use it for the 1st up mag on a stage so I'm topped to 20 and roll with 19 after that. Seems like there should be something better. And maybe those stupid TF cuts in the bottom should not be there and then the inside of the extension could be cut deeper.

By the way... Anyone have a link to where I can get the brass TF extensions? I wanted to pick up one or two to compare to the others in how it gun handled with the extra weight. Anyone have any input as to if they are worth the extra money?

[ryan45kim]

I have 8 M&P 40 mags with TF 140 base pads and they all are 20 round reloadable. You would have to work to get 21 in the mag but it can be done I’ve seen it but don’t think it is reliable so I wont use them myself. The stock springs will work for a while but they are not strong enough to last very long in a 140 mag. You have to use the factory spring to get 21 so I’m told. My gun started out running my mags with the stock springs after using them for maybe 5 months. I do smooth the follower and the transition to the base bad but I do not shorten the follower. The brass pads add a little weight but once I’m shooting I really don’t notice the difference.