FTF S&W M&P 2.0 10mm 4.6"

[PowerDemon]

Good evening everyone,

Thanks for the add.

I bought my new Smith and Wesson M&P 2.0 10mm 4.6” about a month ago from my LGS. I absolutely loved the grip, the trigger, and the cartridge. I had been looking for a gun I liked in 10mm for awhile and once I saw the new 2.0s chambered in 10mm I was on the lookout for one. This is my first M&P but not my first Smith. I also have a 686+ 3” that I cut my teeth on reloading with.

Once I bought the gun I ran about 100 rounds of Remington UMC 180gr ammo through it followed by another 300 rounds of the Sellior and Bellot FMJs. The gun ran flawlessly (besides my gf limp wristing it once) and I was very pleased.

However once I started running “real” 10mm rounds through it the problems emerged. I ran some Underwood 180gr GDs and XTPs through it and they ran OK. I clocked them on my chrono at 1278fps avg. But on the second to last round it would occasionally hang up. The cartridge would catch on the top edge of the bullet on the upper part of the chamber. It did it a total of three times with about 90 of these rounds through it. I thought it was strange that it was consistently the second to last round.

I have also worked up my own reload for the pistol. I am running 13.5gr of Accurate #9 under a Georgia Arms 180gr FMJ with a Federal 155 primer. I have clocked the load around 1230fps. I messed around with the OAL a fair amount to try and resolve this failure to feed issue. I have tried 1.245-1.270”. So far 1.265” has produced the best results with no issues so far but I have only run a few rounds through it. The 1.245” and 1.270” loads consistently hung up on either the second to last or last round. If I treated this gun as a 10 rounder I wouldn’t have any issues!!

In terms of troubleshooting, the problem presented itself with both magazines. I do not think I am limp wristing the pistol but maybe? I had an experienced shooter observe me shooting and he did not have any comments on my grip or recoil control. He did shoot the pistol as well but he only shot two rounds through it. I have cleaned the gun a couple times since I bought it, and I keep it well lubricated.

Basically what I am trying to find out with this post, is if anyone else has had this issue and if anyone has any advise on how to resolve the issue. Thanks for taking the time to read my lengthy post!

 

[dla]

Your slide velocity is higher than what your magazine spring can keep up with.
Usually a longer COL helps, but it sounds like you hit the limit of what your magazine will handle.
My guess is that you could repeat this failure by only loading 3 rounds in the magazine.

So, having said all that, this is what I see your options are:

1. Slow your loads down.
2. See if Wolff or somebody offers extra power magazine springs
3. Pull a magazine apart and clean/lube it. Consider stretching the spring a bit to increase compression force.
4. See if you can find an extra power recoil spring

You might get better results using a heavier bullet at a lower velocity.

Have fun!

 

[PowerDemon]

Thanks for the advise. That actually makes a lot of sense now that you mention the slide outrunning the magazine spring. Especially the failure to feed the last couple rounds.

I was able to consistently reproduce the failure to feed with my reloads on the 2nd to last round. Lengthening the OAL helps a little bit but the gun will still occasionally hang up on the last two rounds. The gun has never hung up on the first 13 rounds, regardless of ammunition.

Do you know anyone making an aftermarket recoil spring for the 2.0 yet? I haven’t been able to find any. Wolff says they won’t have a spring available for it until the summer.

 

[CP38]

I got tangled-up in this same bar fight with my new MP 2 10mm. I believe it is a recoil spring issue, but I sent mine back last week to the factory to hopefully have them resolve the problem. We’ll see…

I purchased my MP 2 to replace my old Glock Gen. 2 model 20 10mm woods carry pistol. My old Glock just works regardless of the ammo it is feed and the environmental conditions in which it is used. It has been a damn reliable pistol. On the other hand my new MP 2 has so many things going right for it, it is really disappointing that it is unreliable with 10mm performance level woods-carry ammunition. I certainly hope that Smith takes this problem seriously and fixes it before someone, while crawling around in the brush, has a nasty problem that requires a reliable firearm.

 

[PowerDemon]

Sorry you’re having issues as well. Please keep us posted on your progress! I am anxious to see what Smith and Wesson say once they have their hands on it.

Were you having the issue with regular practice ammo or full power ammo?

I’m with you. I really like the 2.0 and I want to hang onto it. All my friends tell me I should sell it and buy a Glock 20! I’m not quite there yet but getting close!

 

[hardluk1]

I use ISMI recoil springs in my m&ps and 1911's all a couple lbs heavier than stock . 4.25 core 9mm runs an 18lb spring . 4.25 40sw a 20lb spring , both run fine with standard practice ammo or underwood ammo . A new 5" ported 40sw runs fine with a new 20lb also borrowed from my 4.25 model but then the recoil rod is the same length as the 4.25 models .

If your recoil rod is a bit short of the end of the 4.6" slides opening its the same as a 4.25 and 5" model's . Buy some new 20 and 22lb ISMI springs and try it but remember glocks standard size models run the same springs too and they go up to 24lb . ISMI only sells 20lb for m&p at least untill they manage to add heavier opinions for the 10mm !

Do buy some wolff 45cal +5 or +10 mags springs but you may want an Uplula to help load those cartidges .

This company - Welcome to Centennial Defense Systems - Free Shipping on Orders of $19.95 or more _ will see ready to run recoil assembles but one video on you tube shows a long recoil rod in a 10mm but looks like a 4" model? Should work fine in longer slide pistols .

 

[CP38]

I had a few minor hiccups with my MP 2 10mm during the initial break in sessions, but after 100 or so rounds it ran just fine with lightly loaded range ammunition. However, with real full-house 10mm ammunition it puked routinely. If you do an internet search in this regard, you will discover that we do not have an exclusive with this problem. The best we can hope for is that Smith is not in a corporate-denial mode, but rather is engineering a fix for these otherwise decent pistols.

 

[GTS197]

Similar issue with my 4.6”. Put in a Wolff 22lb spring and guide rod and 10% mag springs. Surprisingly the mag springs were weaker than the factory ones, so I just left the OEM springs in the mag. Tried 6 different factory loads and everything went well, except for the last couple of rounds of 220gr hard cast. Bullet nosing up and catching on the top of the chamber. I have a 24lb recoil spring on the way and I hope that’ll cure the issue with the hard cast loads. We’ll see, I guess.


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[PowerDemon]

Similar issue with my 4.6”. Put in a Wolff 22lb spring and guide rod and 10% mag springs. Surprisingly the mag springs were weaker than the factory ones, so I just left the OEM springs in the mag. Tried 6 different factory loads and everything went well, except for the last couple of rounds of 220gr hard cast. Bullet nosing up and catching on the top of the chamber. I have a 24lb recoil spring on the way and I hope that’ll cure the issue with the hard cast loads. We’ll see, I guess.


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Did they fit as is? If so what part number did you buy? I would love to pick up some heavier recoil springs to see if that solves the issue.

When I talked to Wolff about a week ago they said that they won’t have any recoil springs for the 10mm until this summer. They also said they haven’t been able to get their hands on one to R&D anything yet..

 

[GTS197]

Did they fit as is? If so what part number did you buy? I would love to pick up some heavier recoil springs to see if that solves the issue.

When I talked to Wolff about a week ago they said that they won’t have any recoil springs for the 10mm until this summer. They also said they haven’t been able to get their hands on one to R&D anything yet..

54622 is the sku for the Wolff guide rod and 22lb spring. 54524 is the sku for the 24lb spring only. These are labeled as .45 ACP, but if you have the 4.6” these will fit. Nothing yet for the 4”, as S&W does not have a comparable .45 with that barrel length.


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[GTS197]

Stronger recoil springs don't slow your slide down. They just make them short stroke so the ejector hits less. Strong springs will increase slide velocity going into battery. Springs do not remove energy from a system. You need the slide to bottom out on the frame to decrease the energy the slide is storing.

Since stretching the magazine spring only works for a mag cycle or two, extra power springs are really your only good bet for this ammo.

You’re not wrong. Plus the heavier spring increases wear on the slide stop. I’m just trying to find the sweet spot. I’ll be traveling to bear country next month and my primary load will be 220gr, but am experimenting with others. The 24lb spring may/may not rectify this. I should’ve clarified that in my previous post. I do not plan on running the gun regularly with the heavier spring.


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[PowerDemon]

Stronger recoil springs don't slow your slide down. They just make them short stroke so the ejector hits less. Strong springs will increase slide velocity going into battery. Springs do not remove energy from a system. You need the slide to bottom out on the frame to decrease the energy the slide is storing.

Since stretching the magazine spring only works for a mag cycle or two, extra power springs are really your only good bet for this ammo.

I understand that it doesn’t slow the slide down as it’s closing, but wouldn’t it slow the slide down as it’s going back? If so wouldn’t that be beneficial to give the mag time to press the next cartridge up?

 

[dla]

Stronger recoil springs don't slow your slide down.

Wrong without further explanation.

If the slide only compressed the spring and locked, then the force of the spring slows down the slide - behaving like an increase in slide mass.
But the spring also accelerates the slide back the other direction, acting like a reduction in mass.

What we want is enough time for the magazine spring to lift up the next cartridge.

So we can slow down the slide or speed up the magazine.

Btw, the main problem with heavy recoil springs (aside from battering) is that the "unbalance" causes the muzzle flip to increase both up and down.

Imho, of course.

 

[PowerDemon]

The next round doesn't begin to rise up until the breechface has cleared the rim at the back of the next cartridge. Stronger recoil springs decrease both the amount of time and even the distance behind the rim that the breechface travels before starting forward again. That period is all you have for the mag spring to get the next cartridge up high enough for the breechface to snag it and push it into feed ramp.


Gun makers (good ones, anyway) control slide velocities through slide/barrel mass, not springs. Which is why a Glock 17 (9mm) and G22 (.40) use the exact same recoil springs but a heavier slide for the G22. (Same with the G21 and G20.) With a properly designed pistol, the recoil spring is the proper strength to do one thing - push the cartridge out of the mag and close the breech. If slide velocities are too high, the only way to take away that speed is to make the slide mass higher or to have some sort of elastomer buffer that turns some of the slide energy into friction and heat, slowly destroying the replaceable buffer.


How a pistol ejects or how much muzzle rise it has doesn't really tell you anything about how it is cycling. All the competition tweaking 1911s can tolerate has misinformed the public about how recoil operated firearms actually function.

How much weight increase is noticeable? For example if I added an RMR (my plan before these issues) would that make a difference?