Difficulty with M&P .40 trigger vibration

[fortibus85]

I’ve used the Search function and didn’t find anyone with this issue.

I have a “new” S&W M&P .40 that I bought last Fall but never got to shooting until recently. I was surprised to find after only shooting ~ 100 rounds that my trigger finger was throbbing.
I’m a Glock shooter, only 9mm, but have also on occasion shot .45 in Glock and 1911 forms. Although I haven’t shot much lately, in the last few years I shot several thousand (9 mm) rounds a year while participating in local IDPA matches. I’ve never experienced this. It was like my finger had been asleep and was getting its feeling back.

I’ve had no work done to the M&P, and had already been thinking about an Apex AEK kit, because it comes so highly recommended I have really enjoyed having a nice 4.5 lb pull on my Glocks after a few relativley easy modifications. But frankly, I’m wondering if there is something wrong with my M&P, or everyone who shoots one is tougher than I am, or… ?

I’ll get the AEK or similar replacement kit if it solves the problem, but I’ve never seen anyone mention this so I wanted to ask before I sink some money into it only to find that the vibration to my finger won’t be solved by that. Any insights?

[notorious_ar15]

I know exactly what you are talking about. I had the same issue with my M&P Shield. Installing the APEX Shield Carry Kit, which seems to have eliminated the problem for me.

I did not replace the factory trigger, but may do so in the future - for now, it is fine as is after the other upgrades...

[BKennedy]

Happened to me with an M&P 9mm full-size, felt like trigger slap on an early WASR that a friend owned. S&W wanted to take a look, they sent it back after finding "everything in spec". I had a friend shoot the gun and he experienced the same thing. Sold that gun and never looked back, FWIW.

[cfrock]

I experienced the same a while back on an M&Pc in 9mm that I had. I sold that gun for other reasons.

I'd recommend the APEX trigger. It's a $40 part and well worth it. The M&P guns have become my preferred platform (after APEX's FSS parts).

[fortibus85]

Thanks gents. It's nice to know I'm not crazy, or soft.

[Clint]

My 9c shoots smooth like butter.

The only thing I can think of that would possibly cause trigger slap is the "disconnector" cam on the slide that knocks the trigger bar off the sear.

It pushes the trigger bar sideways as the side goes back.

If that action is not smooth or if the trigger goes backwards instead of sideways, it may kick the trigger, causing the slap.

On an empty pistol, Try pulling the trigger and cycling the slide slow and fast, feeling for any slap in the trigger.

[williejc]

Trigger slap has been reported in several forums. Kel Tec PF9s and CZ PCRs are mentioned frequently. I don't understand what causes it and look forward to reading a good explanation.

[T2C]

Trigger slap has been reported in several forums. Kel Tec PF9s and CZ PCRs are mentioned frequently. I don't understand what causes it and look forward to reading a good explanation.

I would be interested to read a good explanation as well.

[fortibus85]

Follow-up report.

Executive Summary – I’m a wuss. I hate to admit it, but I can’t let S&W take the rap…

Detailed Summary – During the incident in question I had not shot for a year, and fired about 300 rounds of .22 LR on a Sig Sauer Mosquito prior to shooting the M&P 40. Not long after posting I went shooting with the Mosquito only, and found myself working through some discomfort with the Sig. If I place the pad of my finger on the trigger like I am supposed to (rather than my first knuckle like my big hands want to), then I find a surprising amount of vibration as well as that my finger simply does not like the curve of the Mosquito trigger. I got a minor throbbing simply from shooting the .22 (I didn’t mention shooting the 22 in the OP because it never occurred to me in my wildest imagination that it would have been a factor).

So I went to the range a few days later and shot only the M&P 40. Truth is, there is some discomfort/vibration that I don’t like, but it is not unbearable.

I will proceed with my plan to install the Apex DC Kit. In the meantime, I have taken to shooting with a thin glove, which helps quite a bit on the finger and does not bother me at all on my hand.

And I will be archiving this post, in case anyone anywhere EVER accuses me of talking trash.