M&P40 1.0 Ejection Issue

[Chuck Edwards]

A couple of months ago I bought a police trade-in M&P40 1.0, at least partly because it was at a near pre-Covid price. It was in good shape and in general runs well. I replaced the RSA with a green one and the magazine spring. This is my second M&P40 1.0, the first one I bought new and still have.

Fired brass from this gun shows the typical dent in the case that comes from hitting the slide on the way out. As a long-time 1911 shooter, it's familiar. On my last range trip, though, I had one case not clear the slide and ended up on top of the magazine with the primer end facing forward. Not good. My other M&P40 ejects cleanly with no dented cases.

The ammo used was mostly my 180-grain RNL handloads, plus some R-P and American Eagle 180-grain FMJ, plus when I installed the new RSA and magazine spring I ran 46 rounds of 180-grain HST through it. I was shooting my handloads when this happened. My handload was developed to replicate the HST load; when I chronographed it, it was one fps faster than the HST, and I figured that was close enough. The extractor wasn't gummed up with bullet lube, that was one of the first things I checked.

I did a search before posting, and I'm not the first person to have issues with ejection but the consensus seemed to be to just live with it. Since that one case didn't clear, that doesn't seem like a good idea.

Is this an issue with a specific production run? The prefix on this pistol is HVN.

Is this an extractor issue? The extractor and spring look relatively easy to replace. Replacing the ejector, OTOH, looks like it would require more disassembly of the pistol than I'm comfortable with.

TIA!

 

[Lock n' Load]

Apex Tactical makes a product called "Failure Resistant Extractor" for your gun. Because I have no experience with your firearm, I can't say for sure that this is the fix for you but, because you bought it used and have no warranty backup, it might be worth a look. There's also a detailed video on the installation which looks fairly simple.It might also help to use the video instructions to just remove your existing extractor and giving it a good cleaning, as they do on the video, before spending the money on something you may not need. A call to them might get you someone on the phone who can help. Good luck!

 

[robrossk]

Super difficult to diagnose. I have 2 V1.0's and cannot recall a malfunction. I would clean (including magazines), lubricate properly, and fire a lot more rounds before spending $$ on new parts. Could just be a one off issue.

 

[hardluk1]

Hard to say what your problem is caused by . But you might need a new extractor as a last resort but to me even more odd is the brass being dimpled like your 45 ! Or was that with the old recoil spring ? I have 2-40sw m&p's one is about 11 or 12 years old 4.25 model the other a 2.0 5" pc and never had a dimple or extraction issue . My carry ammo is underwood 155gr at 1300fps + while practice amm0 is home rolled 155gr coated swc at 1260fps for the older gen 1 4.25 model . The 5" 2.0 so far has been run with standard velocity 180gr rnfp and hst or ranger t series .

What kind of shape is your m&p in . Holster wear for sure on the exterior . How about wear on the breach face or chamber area and where the hood impacts the top of the breach . Any wear (smilies) on the barrel that seem heavy along with finish wear on the barrel that looks to be from high round count .

Do you know what the poundage is for the green spring . I've run a 20lb spring in my 40sw 4.25 for years and 18lb in out 1.0 4.25 and a 2.0 4" 9mm .

 

[Saudade]

I suggest you remove the extractor and thoroughly clean the channel and spring. Carefully inspect the extractor claw.

When I deep cleaned my 9mm (it was about 1000 rounds) I found an incredible amount of gunk under it. I was not having extraction issues at that time, in fact I was pretty amazed it still worked.

I field strip, clean and lube after every range session so overall my guns are well maintained. So I was pretty surprised how much collected in such a small (and inaccessible) spot.

 

[stansdds]

I am not an M&P owner, but the only S&W I have had so far that would not reliably extract and eject was a transitional 645/4506. The cause of its failures was a buildup of gunk in the extractor slot. A good cleaning cured it.

 

[Tu_S]

I have no way of proving this and have not had any issues with my trade-in M&P 40, but being a LEO trade-in I can picture whoever had the thing before you getting into the habit of dropping a round in the chamber and closing the slide instead of from feeding from the magazine, putting extra wear on the extractor and it's spring.

As far as denting the cases, it is something that tends to happen on my officer length 1911's when I put in a new recoil spring and run the relatively low powered target loads I like through them, with the problem going away after the spring gets a little wear on it.

 

[Chuck Edwards]

Thanks for the replies, working on it!