Update 4:

IT WORKS!

Last time out before today, loaded 5 rounds in the magazine, did its usual hiccup on the second to last round in the mag and jammed the nose of the bullet up into the barrel hood. I cleared it and threw it back in the range bag in disgust.

Today went out with a co-worker who has own YouTube Channel, Chuke's Outdoor Adventures. He has a 4.6" M&P 10mm that has been problem free so we set out to make a video comparing the two. Three different shooters put 400 rounds of 7 different types of ammo through the gun today and not a single hiccup. I'll post a link once he finishes editing and posts the video.

Nothing changed today since I last shot it. To date; back to Smith & Wesson once to have the barrel replaced, replaced the magazine springs with Wolff Extra Power springs from the M&P .45, Galloway Precision 22LB. recoil spring assembly, and polishing of the feed ramp and chamber by me.

It works! I'm happy, I've really wanted to like this gun, 15 rounds of 10mm in a Commander sized package but felt I just couldn't trust it. We shot everything from .40 S&W power level stuff to Underwood 200gr. hard cast, even mixing 3 different types of ammo in the same mag and it performed.

Also shot Chuke's Sig XTen, Springfield XDM 10mm and Gen 5 Glock G20. I was impressed with the XTen but was almost afraid to shoot, afraid that I would have buyer's remorse over my Smith & Wesson. In the end not having buyer's remorse. While similar in size, the Smith does feel lighter and more svelte for a carry gun of the XTen.

So in short if you're considering a 4" M&P 10mm, expect to swap recoil springs, mag springs, do some home gunsmithing and a few hundred round break in period.

Update 3:

Installed 22lb. recoil spring assembly from Galloway. No difference at all. Still consistently jambs the second to last round from the magazine no matter what the ammo.

Wondering what to do at this point. I'm going to try and run the standard magazine spring with the 22lb. recoil spring and see if that does anything. I'm also going to look at it tomorrow under better lighting and see if polishing the feed ramp or the underside of the barrel hood might do anything.

Update 2:

Extra power magazine springs had no effect whatsoever, it still consistently jambs the second to last round in the magazine no matter the ammo or how many rounds are loaded in the magazine. 22lb. recoil spring assembly ordered from Galloway Precision for the next attempted fix...

Update:

Returned from factory, no explanation, invoice states, "Replaced barrel, test fired for function"

Range trip tonight, point of impact now matches point of aim. The pistol still consistently fails to feed on the second to last round from the magazine. Does not matter how many rounds are loaded in the magazine, does not matter which magazine, and does not matter which type of ammo, it jambs the nose of the bullet up against the underside of the barrel hood with the base of the case still in the magazine. Dropping the magazine allows the slide to move forward and chamber the round.

Ammo fired tonight was;

Underwood 200gr. Flat Nose Hi-Tek Coated Hard Cast
Ammo Incorporated 180gr. Flat Nose
Federal American Eagle 180gr FMJ

At this point I'm kind of at a loss of what to do. I may try sending it back to Smith for a second time or I may try respringing it. Galloway Precision now offers recoil spring assemblies for the 4" M&P 10mm, Wolff offers extra power magazine springs for the .45ACP magazines that work in the 10mm.

Original post:

So made it out to the range tonight withy new 4" M&P 10mm and it was not a happy range trip. Gun was cleaned and lubed prior to shooting. Ammo used was Underwood 180gr. FMJ flat nose, 200gr lead flat nose and 220gr. lead flat nose.

The good:

Very soft shooting for a 10mm.

Practical size; small enough to conceal and big enough to be comfortable to shoot.

Runs flawlessly until the second to last round in the magazine.

The bad:

Consistently low point of impact with all types of ammo.

Consistent failure to feed on the second to last round in the magazine. Does not matter how many rounds are loaded; 5, 10, 15 it always chokes.

50% failure to feed on the last round in the magazine after the second to last round is chambered and fired. The jam on the last round is a little unique, a live round sticking out of the ejection port straight vertically.

I'll be contacting Smith & Wesson's customer service. I really want to like this gun and be able to carry it. But as it stands right now it's not usable or reliable.

I had some of the same issues with early m&p full size 4.25" 40sw when I moved to underwood ammo type 155gr years ago and hotter home rolled loads and found I really needed a heavier recoil springs and then mag springs hadthe same issues your having . I changed the mag springs to wolf +10% springs in all 4 of our m&p's . Only down side is getting those last couple rounds in with out a uplula to help load with for a while . Wolff has heavy 45acp springs that would work !! I use ISMI recoil springs for whats that were . Clean your mags inside too and debur the follower if any edges can be felt .

Shooting low?? is your weak hand index finger on the outside front of the trigger guard? This can cause consistent low hits on the target.

No it was not. I typically wrap the index finger of my weak hand up underneath tight against the underside of the trigger guard. I had two other handguns I was practicing with during my range session; a Browning Buckmark and a Ruger GP100 in 10mm and was shooting both to point of aim. The gun club instructor had the same low point of impact with the M&P that I did.

Is the gun factory new, or "new to you"?

Have you tried any other types and brands of ammunition? Several complaints/gripes here on the forum within the past few months concerning failures and problems with the Underwood brand. (10mm)

Many other comments about the OAL and bullet style of the malfunctioning ammunition, along with other possible concerns like extractor fitting, guide rod assembly, and magazine springs, etc.

__________________
Ret. LE, FA Instr, S&W Armorer

The pistol is factory new, first time out with it. Haven't tried any other types of ammunition yet. I figured if issues would arise it would be with hotter loads. Living in Alaska, kind of limited in what I can get for 10mm ammo. Most on-line retailers will not sell here due to the difficulties of shipping ammo to Alaska. That leaves us with local retailers. Buffalo Bore and Underwood are both stocked by a couple of retailers here. Having experienced blown out primers with Buffalo Bore in my Dan Wesson Razorback, I was not wanting to go down that road again.

Combat sights.

Smith have been fitting "cover to kill" sights for a while. If you are using a six o'clock hold, the point of impact will be low.

__________________
Release the Kraken

I purchased the 4.6" version and couldn't be happier. Already added a Holosun 507C Red Dot to the topside. Shoots nice and adjusted the red dot to point of aim.


Not criticizing your shooting style, but low hits are often caused by "looking over the sights" to see point of impact "before" pulling the trigger. I have been guilty of that crime while testing new loads for USPSA competition. I shoot a lot of high power revolver calibers that also create that muzzle down reflex while pulling the trigger.

It's back from Smith & Wesson. No explanation, invoice only states, "Replaced Barrel". The feed ramp does appear to be more polished than the original. Hoping to get out to the range this weekend to try it out. I'm also thankful to have it back after numerous e-mails from FedEx with warnings of adult signature and ID required, they just left it on my front door step.

I've been doing quite a bit of research online. Seems the second to last round in the magazine failing to feed is a common problem. One fix has been stronger recoil springs. Lots of kitchen table gunsmithing of taking apart the the recoil spring assembly and reassembling with a heavier Glock spring. Galloway Precision now has heavier recoil spring assemblies available for the 4". The other fix has been to replace the magazine springs with Springer Precision or using the extra power Wolff springs from the .45ACP M&P magazines.

Hoping it functions, I really want to like the gun.

Thanks for the info, going to order a 20lb & 22lb recoil spring assemblies for my 4". Plus look for some mag springs from Wolff Springs. Much appreciated!


Do you know what the stock spring is #lb(17) ?

Before you spend more of your hard earned money for parts, why not contact S&W Customer Service and send it back to them for warranty repairs. Several Forum members have done this, and their 10mm and magazines come back with a polished feed ramp and new springs. I just bought a 4.6" bbl. 10mm but haven't been to the range yet. I will be shooting factory ammo, too (Federal 180gr). I'm hoping my functions flawlessly! Fingers crossed. Good luck.

Smith & Wesson customer service is awful, thats why(In My Experience). Not sure whats happened over the last oh 3yrs, but it is what it is.

A little thing called the COVID-19 pandemic, that's what happened. Employees out sick, mandates restricting how many employees can be onsite, physical distancing between employees and masking requirements have been a hard hit to a lot of businesses. Couple that with panic buying and firearms companies being slammed with orders for new firearms and you have a recipe for poor quality control and customer service problems.

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VCDL, GOA, NRA

Update at Top

I ordered the 20lb & 22lb recoil spring assemblies for my 4" last Friday from Galloway Precision, see how it goes with my failure to feed on occasion. So the Wolff .45acp mag springs will work for the 10mm?

Sounds like weak magazine springs to me

Possibly, going to order some as well.

Could save some time by cleaning and lubing your magazines - just a thought.
Johnson's Paste Wax, Lucas Slick Mist, any Teflon or Silicone spray will work.

dry lube! I use Liquid Wrench dry lube, grey label with PTFE and boron nitride (aka white graphite)

excellent lube for anything rimfire, or trigger assemblies, and inside mag tubes and on the springs/followers ESPECIALLY metal AK followers.

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NRA RSO

Update 2 at top.

I just purchased the new equalizer and the springs in the mags are super strong getting the last three rounds in using a maglula is tough. My buddy went shooting with me he has the shield plus which uses the same mags and what a difference between them. The first time I loaded the 15 round I didn't count and I only loaded 13 very difficult to load the last few sure it will get better.

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How many rounds have you shot through it?

As of today 350 no issues at all.

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Once ya'll and S&W get all the bugs worked I'll probably buy one. For now my 1006 and 1911(10mm) flawlessly fill the bill.

__________________
S&W Accumulator

If it's any consolation, the guys over at SigTalk are having similar problems with their P320 10's.

I am a huge fan of all things Smith & Wesson, and I have had quite a bit of trigger time with 10mm handguns. I would very much like to add a 10mm M&P to my collection of pistols, but with all of the reports of problems I simply can’t bring myself to do it. It just doesn’t seem to make any sense that Smith & Wesson can’t get these pistols right.

Glock has been selling the model 20 and 29 for a long time now, and nearly everyone who’s owned one has nothing but great things to say about it. I’ve also seen a lot of positive praise for the Springfield Armory polymer pistols in 10mm. Unfortunately, I have no desire to buy a Glock or a Springfield. I want a Smith & Wesson. I just don’t want one that can’t be trusted to work reliably. It is very disappointing to see that people are still having all of these problems with their 10mm M&P’s, yet every time you turn around, S&W is announcing the release of some new pistol.

I’d really like to see them slow their roll, and address the shortcomings in the products they’ve already released, rather than continue to rush half-hearted designs to the market only to further tarnish their once great reputation. Fix the second-to-last round stovepipes on the .380 Shield EZ. Fix the trigger on the CSX. Fix the reliability issues with the 10mm M&P. Then, I’d be more excited about new stuff.

Sorry to hear that you’re still having trouble. I’d love to see these issues resolved so that I can buy an M&P 10mm for myself.

I just took my new M&P 4" 10mm to the range. I had heard all kinds of stories about reliability problems with full power rounds, so I replaced the magazine springs with Wolff plus power mag springs meant for the 45 acp.

I didn't have a single failure to feed using both Underwood 180gr range and hollowpoint ammo. I did have an unfired cartridge ping off of my forhead while firing, though. Only happened once in about 200 rounds of ammo. Was a surprise, to be sure. The spent casing ejected, then a live one was flung straight back to hit me square in the head. Somewhere in the middle of the magazine.

Mine was shooting very low at 7 yards; printing 3-4 inches lower than point of aim. I found that if I split the forward dot with the top of the read sight, it goes right where it should. The extra tall sights really bug me, and I am not sure I'll put a red dot on it. I need to figure out what size sights to replace them with.

Oh, and I have a 22 pound spring on order, but other than that one mishap, things went well with the stock recoil spring.

I forgot to mention that with the plus power mag spring, I can only get 14 rounds in the mag.

Update 3 at top.

I suspect that you are battling a Magazine design problem. It's a pure guess but I suspect feed lips that are about 1/16 inch too short for the 10mm length. Unfortunately you don't have the option I use for this type of problem by purchasing Wilson Combat magazines. One thing you could try is to find a gunsmith who has a TIG welder and a willingness to do some modification to one of your magazines. If that one works properly then give S&W a call and explain the solution you have found to them. Hopefully that will push them into modifying the tools for these magazines to provide longer feed lips. If not post the solution here for the whole world to see.

BTW, my BIL was JAG at Eagle River for 6 years, when you folks get cold it truly is very cold. My sister once took a pot of boiling water onto the deck and turned it over from waist height and not one single drop of water hit the deck. On the plus side the scenery in the summer is fantastic.

I'm pretty sure you may have already seen this video, but it sounds like the problem you're having is widespread among owners.

One of the interesting things they mentioned is that the guns seem to feed .40s&w ammunition without issue, so the problem may be linked to the follower/feed lip design. Because of the type of malfunction you are having, the problems could logically be attributed to the magazine, the mag spring, or the follower.
Please let us know if you get this sorted out. Thanks

One other solution provided by one user was installation of Springer Precision magazine springs.

Carter

__________________
Ret. LE, FA Instr, S&W Armorer

I have a 4.6 that I also had the infamous nose up jams with full pressure underwood loads, I did the mag spring and recoil spring, polished the feed ramp, it helped but I still had occasional nose up jams, I reinstalled the original mag spring but kept the heavier recoil spring. I made one little modification to the mag and it's been 100% ever since. 220gr underwood no problem. What I did was take a piece of 220 grit sand paper and carefully sanded the inside of the mag feed lips perpendicular to the bullet case feed direction to roughen the inside surface , that increases the case to mag lip friction enough to keep the round where it should be during recoil. It has been 100% reliable with hundreds of underwood rounds through it. hope somebody else tries this I would like to know if it works for you also.

I haven’t seen a lot of new posts from people saying they have problems with their 10 mms.
Does that mean the factory is getting things straightened out, or does it just mean people stopped buying them for now?

This is crazy smith needs to make the necessary repairs to the pistol that he purchased. I know Walther has better response times than Smith does.

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It's not only S&W, Chuke on YouTube tested a new Gen 5 Glock 20 and he was getting nose up jams using Underwood 200gr hardcast. I've heard of the Springfield XDM and new Sig 10mm also having problems.
The problem originates from having factory 10mm ammo that the majority of is loaded to 40 S&W velocities and gun manufacturers are building for those velocities. I think the crazy part is that if they built to run full 10mm it would still run the low velocity stuff. ***!

Update #4 at top

So if nothing has changed, why does it suddenly work?

__________________
Release the Kraken

I have no idea. Additional time for the spring to take set? The last time out prior to this I literally shot 3 rounds through it, had the jam, cleared it and put it back in the range bag in disgust. Definitely not a thorough evaluation after I had done the polishing.

Sometimes in life you don't question things and go with them.

I went down the 10mm road and was dissapointed. I bought a 4.6 new in April, expecting it to be a good gun, because the 4.6. However through 2 trips to the range and about 400 rounds it was failure after failure. Sent it back to S&W and after zero communication from Smith(only Fedex that it was coming) I got it back. 100 rounds of Freedom Munitions(yes its weak) and several failures on the 13/14/15 round. Magtechs (180 at 1200 per box) were flawless. S&B (180 at 1230) were also flawless.

The paperwork with the gun on return showed they reamed the barrel and chamber. However they also changed the recoil spring. There is no longer an Orange dot on the spring/assembly, but they did not admit that. The spring by my calibrated hand is noticably heavier. Maybe they are tinally making changes and these guns will be right. I got information from here and wanted to post my experience. Maybe it will help others

When I sent my 10mm to S&W it returned with a new recoil spring also. But no mention of it in the paperwork. Original also had a red dot/ring on it and the new one doesn’t.


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I bought a 4" M&P 10mm in February of this year and it has been awesome in every way. Great ergos, very accurate, perfect reliability, and lighter than expected recoil. The trigger is the best of any factory striker fired gun I have ever shot. Its better than all my other centerfire semi autos except my Springfield 1911 .45. I hated the looks of the tall suppressor sights but they really help my shooting.

100% a magazine issue. Tried heavier Springer Precision magazine springs and 22-24# slide spring. Still got FTF on heavy Underwoods. Inadequate surface area & friction on the feed lips. Recoil is causing the next round to slip forward in the magazine, then slide return rockets it high on the feed ramp. Followed this advice and slightly abraded the inside of the feed lips, so far 50 hot hard-cast with no issues.

I used springer extra power springs and it entirely fixed the FTF issues. I has to be a mag spring issue.

Which high power Wolff spring are you guys using? The. One for the 10 round or 14 round 45 acp magazine?

Can you give me more details? Where did you buy them? What is the P/N? I just bought a brand new 4" model, and while shooting ~135 rounds, I had next-to-last round FTF occur three times.

I was shooting S&B 180gr FMJ.

My habit when shooting FMJ is 5 rounds at a time, so for the first firing of the new 10 mm, I just loaded 5 rounds. That was the first occurrence of FTF. For the next ~130 rds, all but one or two loadings were full 15+1, and it occurred twice then.

At least I know I can get off 13 shots. That's double what my Shield 40 can do.

EDIT: Did you use Springer Precision 11 coil, SP0168?

Or SP0436? I see this one listed on Springer's site for 10mm, but I have seen other owners elsewhere reference the 0168.