Does Smith have a factory recommendation on replacement of recoil spring, and/or what might be considered barrel bushing (if it were a 1911) wear? Kimber says replace spring after 1000 rds on their new "solo" model. How many rds is my m&p .40 good for without starting to replace parts? I love to shoot it with fairly mild handloads (165 gr Berry's and Min. amounts of TiteGroup or AutoComp). I guess I could do a statistical analysis of group size in a machine rest every few hundred rounds, but I'm not.

I can tell you that my M&P .40 FS has over 15,000 rounds downrange in USPSA/IDPA matches with no hiccups ever and still has all the original springs.
Probably not recommended ....however it still performs flawlessly so I will keep going until it no longer functions and then change out springs.
Randy

I've got the suggested change intervals on the springs, but don't have them handy or remember the intervals. Figure around 10-12K replace the recoil spring assembly & trigger return spring. BTW, the issue with weak recoil springs is excessive slide velocity and frame damage. A recoil spring assembly is <$10, a frame is around $200. Your choice.

The life of a recoil spring is highly variable due to differing designs. Itty-bitty guns like the Solo are much harder on recoil springs and require more frequent replacement.

1911's had barrel bushings because when they were designed, the through hardened alloy steels of today weren't even a metallurgists wet dream. The barrel bushing was a sacrifical part to achieve an acceptable fit between the barrel & slide (which was surface hardened). The steels now in use show little wear from the comparatively low operating loads of the slide & barrel interface. I'm aware of one pistol that approached 100K rounds without significant changes in group size.

Why not replace stuff when it starts giving you problems?

Pretty sure the official test from S&W for the recoil spring is to face the gun to the sky and drop the slide with your thumb. If it loads a round it's still good.


Other than that...I'd just shoot the living snot out of the gun and when you hit 100,000 rounds I'd say think about replacing stuff.

Just keep an extra spring around. No need to wait until something breaks.

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NRA Certified Instructor

Finding out you should have replaced normal wear parts in the middle of a gunfight is not a good thing. A new recoil spring assembly is <$10, 10-12 k of ammo is ~$2,000+. Preventative maintenance prevents failure to function as designed. Do you wait until you have an accident to buy new tires? Run out of gas before filling the tank?

With a captive recoil spring, I expect a spring compressor with a load cell would be used. With a non-captive spring, comparing the current spring to a new one of the same specification is the standard. Replace when the old spring is 3/8-1/2 inch shorter than a new spring.

The same springs may fail at different rates. Some may go 10,000+ while others may start getting tired at 4,000. I'd say if its a carry gun, split the difference and consider changing at 5,000, but thats just me. I'm also interested in what S&W recommends. In the last Glock Armorer's course I attended, the instructor said that Glock recommended they be changed every 4,000. And that was before the 4th Generation problems.

In the armorer class I took when the M&P pistols were still fairly new, as I recall the recommendation given in the class was to replace the recoil, trigger, striker & mag springs at 5,000 rounds or 5 years of LE use, left loaded all the time. (I'd have to dig out my notes to confirm, but I believe the striker spring was included.)

We were also told that springs in guns that had been used for testing and used in competition had been running normally longer than that, though.

Once S&W started using a round count/time-in-service replacement recommendation (versus the old fashioned recommendation of comparing an old spring to a new one, which wouldn't work anyway since the M&P RSA is captured and not free), they seemed to be inclined to err on the conservative side of replacement intervals for pistols carried for dedicated defensive purpose. Understandable.

Personally, I tend to err on the conservative side of such things, myself, especially when using higher pressure loads or more compact models ... or anything chambered in .40/.357.

I'm about due for a recert class for the M&P, so I'll be interested in seeing if they've changed their official recommendation for spring replacement.

In Glock classes you could hear quite a range of recommendations for spring replacement over the years. I have a wearable parts replacement schedule for the Gen3 (and earlier) .40's in LE use (from sometime in '08) that lists RSA replacement at 2,500 rounds for the G22; 2,000 rounds for the G23; and 3,000 rounds for the G27. (The firing pin spring was listed for replacement in all .40 models at 5K rounds, BTW, as well as some other springs and the locking block pin.) My last Glock recert was earlier this year, and they just covered the Gen3 & older models by saying the recommended replacement interval for all those RSA's in all calibers was between 2-3K rounds.

I've heard replacement recommendations for the Gen4 guns running from 5-7K or 6-7K, depending on who I was listening to from Glock. They've been revising the RSA's for some of the Gen4's though, especially the 9's, so we'll see if the recommended intervals change at some point as they get some time on the newer RSA's.

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Ret LE Firearms inst & armorer

Hi guys, me, being a newby and not being as knowledgable about my M&P 9 as I would like to be, wonders if S&W would sell a 'maintenance' set of sorts. A pack of replacement springs etc..? This is my very first gun so I probably tend to 'over nurture' it?

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dsblignaut M&P9

Do new tires mean I wont get in an accident? Nope. Just means I spent money I had to spend.
Gas...well I have a sweet way to measure that with a proven record of success. You might not but I have a sweet meter in my vehicle that tells me when ill run out. I even have a light that comes on when I'm close to empty. If only my gun had one.
IF I get into a gun fight ill trust my gun in stock form. Why? I've shot it at the range a lot.

Feel free to replace parts as you wish. Maybe even once a year. Whatever your schedule becomes, stick to it.

I replace recoil springs at around 3,000 rounds no matter what. At $5 or so per spring, I figure that might put me at one spring a year IF I do a lot of shooting with that gun.

I am a handgun collector so few if any of my guns see more than 3,000 rounds a year.

OK, I did some research on this. There was a 62K+ test run on a M&P9 a couple of years ago and based upon various incidents and factory directives/suggestions, the following:

Recoil springs, 7500 rounds "in severe service". (Per Factory at that time).

Trigger return spring, 15K. I think this would be an excellent time to also replace the striker spring.

The slide catch/release/stop should be replaced somewhere around 15-20K. Lean toward the 15K for caution.

The magazine catch may or may not be an issue for you. It's less than $5 if it is and will take longer to explain how to change it than to do it. See your manual.

The factory may have adopted portions of the suggested PM plan for the MP series that they used for the 3rd generation guns. They don't want to get sued, so the suggestions may be conservative. On the other hand, the wear parts on an M&P won't break your budget.

What's the difference in colors on the MP 40 recoil springs?

I love Smith M/P but you cant get springs and some parts for them its some kind of big deal . Glock you can .

On my 9 Core, I've got over 80K rounds on the recoil spring assembly. When I called Smith a while back regarding replacement recommendations, they said they test the flat wound springs to 50K and then stop. They don't find any difference in testing the used spring compared to a new one. So I'm using the Core as a test. I shot it for 2 competition seasons without any problems. It's now my wife's gun, and my match backup gun. My new competition pistol is 9 major and I'm always screwing around with different compensators, different springs, and different loads so I have no idea of the round count, but Major power factor loads hammer everything on the pistol so I doubt I have more than 5K rounds on the springs. My carry and HD guns don't have nearly the round count as my "fun" guns so I'm not worried about them.

Like Bkreutz I also screwed around trying to get the right weight recoil spring when I put a comp on my 9 Pro. Well after a time I no longer knew what spring was what weight so I developed a recoil spring weight tester. I can now measure them down to the ounces so should be able to track wear. Don

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USN Retired/VN VET
M&P X5