Problem with M&P 10mm + Customer Service Nightmare

[rosewood]

I have a thought, is it possible that the 220 bullet is fatter/wider in the magazine and possibly engaging the mag release within the magazine when the next round slides by? The profile of the bullet is too wide?

This may not be a gun defect at all, but an incompatibly of the bullet profile and the magazine??

Look in the mag catch hole on the mag and see just how close the nose of that bullet is to the side of the magazine and compare to other bullets. See what happens when you remove one round and just how close the bullet is to the hole.

Maybe someone that reloads and has had this problem could try seating the bullet deeper and see if it mitigates the issue.

Rosewood

 

[mark_lives_things]

I've said all this before, but I understand this thread is getting long, so I'll recap again here:
-This malfunction has presented with all three rounds I have tried: S&B 180 grain JHP, Underwood 200 grain hardcast, and Underwood 220 grain hardcast
-The heavier loads induce the problem more consistently (but it happens with all three)
-A one-handed grip induces the problem more consistently (but it happens with a two-handed grip, too)
-Everything about the pistol is stock, and every round is within SAAMI pressure specs.

 

[Tannhauser]

I've said all this before, but I understand this thread is getting long, so I'll recap again here:
-This malfunction has presented with all three rounds I have tried: S&B 180 grain JHP, Underwood 200 grain hardcast, and Underwood 220 grain hardcast
-The heavier loads induce the problem more consistently (but it happens with all three)
-A one-handed grip induces the problem more consistently (but it happens with a two-handed grip, too)
-Everything about the pistol is stock, and every round is within SAAMI pressure specs.

Thanks for the clarification.

It's really unfortunate this problem is sticking with you over two different pistols.

I think that the problem lies with the recoil spring assembly and possibly the mag catch design.

If it was my gun I'd try a heavier recoil spring, because that's what I've already done with my 4.6. I understand the thought behind wanting a stock gun that works with all ammo. Maybe S&W will get there with some updates, but I imagine this will be a slow process.

 

[rosewood]

I've said all this before, but I understand this thread is getting long, so I'll recap again here:
-This malfunction has presented with all three rounds I have tried: S&B 180 grain JHP, Underwood 200 grain hardcast, and Underwood 220 grain hardcast
-The heavier loads induce the problem more consistently (but it happens with all three)

I apologize, I had read that but forgot about your earlier explanation.

Rosewood

 

[mark_lives_things]

I apologize, I had read that but forgot about your earlier explanation.

Rosewood

No worries, like I said, I know this thread is getting long.

 

[Tannhauser]

Any updates from S&W on your current issue?

I was at the range yesterday with my M&P 10, and myself plus a another RSO attempted to duplicate your issue. Couldn't do it. Mags full, mags almost empty, strong hand, weak hand, etc. Zero issues except for 1 round that had a primer issue.

Of course I wasn't firing 220 gr hardcast either. Not trying to discount or minimize your issue, just at a loss for the cause.

 

[mark_lives_things]

No update, but he told me he was headed out on a trip and I wouldn't hear from him until next (this) week.

What ammo were you using? And any chance you'll be able to test with some heavy stuff?

 

[Tannhauser]

I was shooting 180 gr JHP handloads. I'm using a max book value of Blue Dot, which is giving me a hair over 1200 fps from my 4.6" barreled M&P 10. I know Buffalo Bore and Underwood sell hotter 10mm in the 180 gr flavor, but lacking their research and possibly canister powder, I'm sticking with book max.

I do plan to try out some Underwood or Buffalo Bore 200 gr hardcast at some point. I don't plan to go as heavy as 220 gr.

I will add I'm not using the factory recoil spring. I'm using a Wolff guide rod and 22# spring.

 

[Old Navy]

I talked to friend today who was just back from NRA meet in Texas and had a chance to try a 10mm M&P 2.0 to see if the problem my M&P had in my opinion was a weak recoil spring. His conclusion, he's in charge of production for a factory that's part of large European gun company, and he said he thought the gun was using too light a recoil spring, probably from a M&P 45 was his guess. Mine is an optic ready 4.6" model and other than that no problems.

I was shooting some old Win JHPST I got in mid '90's or early 2000's that are 180gr IIRC, on my back deck and wife said they were hitting about 20' away to about 15' away with sub-sonic ammo which in my 1911 drops about 5' from me.

I had same problem a CZ75 that was originally sold in '06 that I recently bought. I bought a Wolff cal pac and ended up using a 20lb spring to get it under control.

I plan on calling S&W to find out what poundage their spring is and find a replacement, if possible, from Wolf. Otherwise, I'll shoot it till it breaks.

 

[Execpro]

Had a 1006 that, as it cycled would bounce a round from the mag to the ground and load another as it should. This only happened with the 2 hottest 10mm rounds at the time (early to mid 1980’s).
The gun came with a 18lb spring. The issue was the recoil spring was to light and the slide hit the frame to hard. A heavier recoil spring was the
solution.
As mentioned above, I would also check mag release fitting to the mag notch to insure complete engagement.
This is something you can do at little expense.

 

[GTS197]

I plan on calling S&W to find out what poundage their spring is and find a replacement, if possible, from Wolf. Otherwise, I'll shoot it till it breaks.

Not sure if it was here or on another forum, but someone called and they refused to divulge the spring weight. He persisted and finally got S&W to admit it was a 17lb spring.

Disclaimer; I have only seen that mentioned ONCE, and other than the thread it was mentioned in have no way to validate that the information is accurate. Just wanted you to have a jumping off point.


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[rosewood]

You can't fix a design problem with a stronger recoil spring. Springs don't make the energy go away.

Battering the frame from weak spring could be an issue.

 

[rosewood]

When I bought my witness 10mm many moons s ago, the slide felt like it was bouncing when shooting. I upgraded to 20 or 22 lbs spring and it cleared it up and had shot flawless since. I bet they had a 45 spring in it.

 

[Tannhauser]

You can't fix a design problem with a stronger recoil spring. Springs don't make the energy go away.

What’s the purpose of a spring? It’s a mechanical device designed to absorb, store and the release energy. If your problem is too much energy, a heavier spring is EXACTLY what should be considered. It’s entirely possible that a heavier recoil spring is not the panacea to any problem with a semi auto, but to state a stronger recoil spring can never be of benefit disregards the laws of physics.

 

[Tannhauser]

The problem is that it doesn't permanently absorb any energy - it returns it all as increased chambering velocity. On some guns that means broken lower barrel lugs.

Stiffer springs also cause the slide to not travel as far to rear, causing ride over feed jams.

The weight manufacturers select for recoil springs is based on the desired force to feed and chamber the next round. Slide opening velocity is controlled by slide mass - which is probably why the 10mm M&P is 2.3 oz heavier than the same size .45 version - and uses the same recoil spring.


You are correct that a stiffer spring may change the dynamics of how the pistol is malfunctioning enough to get it to work. But it really isn't working right at that point, just not dropping the mag anymore.


I just found the "undersprung" comment by the gun company employee odd. Every Glock from 9mm to 10mm uses the same weight spring, but different weight slides.

And Glock 20s are under spring from the factory for heavy 10mm loads. Google it and you’ll find there are plenty of posts about G20s, heavy 10mm loads and recoil springs.

I know a couple of different guys who are serious pistol shooters/reloaded and carry G20s for hunting or as bear defense, and they’re carrying heavy bullets loaded hot -Buffalo Bore, Underwood or equivalent handloads.

They are all three using aftermarket recoil springs heavier than the 17lb stock spring. There’s no exact consensus on that’s the “best” recoil spring weight, so I do think the answer is probably “it depends”.

 

[rosewood]

The problem is that it doesn't permanently absorb any energy - it returns it all as increased chambering velocity. On some guns that means broken lower barrel lugs.

Stiffer springs also cause the slide to not travel as far to rear, causing ride over feed jams.

The weight manufacturers select for recoil springs is based on the desired force to feed and chamber the next round. Slide opening velocity is controlled by slide mass - which is probably why the 10mm M&P is 2.3 oz heavier than the same size .45 version - and uses the same recoil spring.


You are correct that a stiffer spring may change the dynamics of how the pistol is malfunctioning enough to get it to work. But it really isn't working right at that point, just not dropping the mag anymore.


I just found the "undersprung" comment by the gun company employee odd. Every Glock from 9mm to 10mm uses the same weight spring, but different weight slides.

If the load is slamming the slide to the rear and battering the frame, either you need to lighten your load, add a buffer of some sort, add a compensator or change the spring. You will either batter the frame to the rear or the barrel lugs. Something is going to be abused. The trick is to find the happy medium to divide the load between the 2 to maximize gun life and reliability.

Contrary to popular belief, the factory doesn't always get this right. They also make mistakes and sometimes install the wrong spring in a gun. Most manufacturers use a different spring dependent upon the cartridge the gun is chambered for. S&W for sure did this with 3rd Gen Smiths.

Rosewood

 

[Old Navy]

All 3 of my 10 series guns needed heavier recoil springs as did my 3 Glock's. I did replace the model 29 spring with heavier spring also and it functioned perfect. As with all my Glock's and S&W's until the M&P came on the market, I could never shoot one and hit anything. Seems being a 1911 shooter since an early age thanks to an uncle with a 38 super when I was a pre-teen and thanks to US military over those many years I had too much retraining required.

Anyway, the spring according to Wolff is a 16lb's for 45ACP 4.6" model and since mine is 4.6" I'm going to go with a 20" for use with 1000fps to 1100fps plinking loads, not hot stuff my 5" 1911 is set up for with 24lb spring.

They don't make cal packs and it requires their guide rod, so I ordered the guide rod and spring combo with 20lb spring and the 22lb spring in case the 22lb is needed so gun could be used with PD loads like my Underwood solid coppers used as 2 or 4 legged stoppers.

 

[safearm]

I'm somewhat late to this discussion, however, I agree completely with the OP, the pistol should work without modification as it comes from the factory.

finally got S&W to admit it was a 17lb spring.
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I don't have a polymer frame 10mm from any manufacturer, mine is a SIG 1911, and I use a Wilson Combat 22# recoil spring. Even with that weight of spring, the cases fly 20+ feet (Remington 180 grain FMJ @ 1150 fps). If S&W is actually using 17# recoil springs, I can see how the frame would flex enough to allow the magazine catch to release the magazine.

Again, to support the OP, it's not his obligation to start changing out recoil springs on his new pistol, S&W should provide the right weight from the start. But those of us who have shot for a long time know that part of the enjoyment is the ability to customize your firearm to exactly what you want. One of the problems of buying a recently introduced model is the lack of accessories, from holsters to magazines (as experienced by the OP) to custom parts (springs, magazine catches, mag wells, etc.). In a year from now, there will probably be a number of parts makers that will have solutions to this problem.

 

[Frank Black]

* * *
Has anyone considered that Buffalo Bore might not actually be compatible 10mm ammo? That guy takes a lot of liberties, inventing fake +P ammo and selling 9mm rounds that won't chamber in many common weapons. He's not really a modern ammo manufacturer as much as a high volume wildcatter.

Ah no, dude.

BB 10mm ammo is GTG.

He should poly-coat his heavy 10mm HC boolits for better feed-reliability and less leading-up of the barrel but chooses not to, whereas Underwood does.

Just FYI: ...

Well-known, long-time Alaskan bear guide, Phil Schmaker, used a 9mm S&W 3913 (an 8+1 single-stack, I think) to stop a Grizzly Sow's charge using BB's 9mm 147grn HC ammo.

He expended all but one round, saving the two people he was guiding ... who (stupidly) were unarmed.

 

[Old Navy]

I use poly coated 180gr for plinking and Underwood Solid Copper specially designed to give devastating hydraulic cavitation and still meet FBI penetration guidelines. My 9mm same way, except I use whatever is cheapest for plinking but generally 115gr and Underwood Solid Copper 95gr IIRC rated 1475fps and they sure go where pointed out to 40n yards with little to no drop.