Took my brand new Shield Plus to the range last night with 115grain Blazer Brass 9mm. First shot out of the 13 round mag was a double feed. Finished the 12 other rounds no issue. Second mag (10 rounder) had one double feed a few shots in. 3rd magazine had one Failure to Extract. Shot about 100 more rounds after that without further issues.

Is there a break in period?

I own a first gen M&P 9mm full size and first gen M&P Shield 9mm (3.1 inch) and neither of those guns has had any major malfunctions with the same ammo or any other ammo.

Is this a known issue? My other guns never needed to be broken in.

I have two new shield pluses,- one standard 9mm, the other a PC 9mm. The standard shield with 200 rounds Blazer 124gr, perfect. The PC shield, one FTE out of 100 rounds using Red Army 124gr. Curious! Gonna run a couple boxes of Blazer 124gr in it and see if it happens again.

I've seen reviews where things were buggy in the first few mags.

Did you add lubricant first or go straight from the box to the range? Sometimes that makes all the difference.

I cleaned, lubed and headed to the range with my Shield Plus. Shooting 300 round rounds of 124 Lawman and 40 rounds of Gold Dot 124. Not one issue. .
I have since sent approximately 1000 rounds down range without issues.

I put some Benelli oil in the slide rails, barrel, and barrel hood first.

I'll try 124Gr to see if it makes a difference. Never had issues with 115 grain before in any of the other 3 9mm pistols i own. I have a full size m&p, an original shield, and a Glock 17.

I ALWAYS take my new S&W mags apart and check them out before using them. Have had to trim some extra plastic off the followers and the mag bodies
themself are not as smooth inside as they used to be. I run a patch with Rem oil with Teflon through them and then a dry patch to get out excess oil. Also put some on the follower and wipe off excess.
This process also ensures that the mag is assembled properly.
Just Sayen.

I'd be surprised if you continue to have issues. Mag springs are very stiff at first, which can be problematic. Fill your magazines and let them sit full for at least 24 hours, then try again.

Once you've let your mags sit while full, especially after you run each mag a handful of times, your Shield should eat everything you feed it.

I took my shield to the range for the first time since I purchased it last March...finally got out.

I had my 13 mag fully loaded with +1 in the chamber. First shot fires, then gun jams. Happened every time I did 13+1. Flawless with 13 or 12+1. Why? I don't recall if I tried using my 10 with +1 or not...I can just know not to carry with 13+1, but also capacity is why I got it, so I don't want this to last forever.

Thanks!

I have had some Pistols that run great right out of the box. Then I have had some that needed to be broke in. I have two Kimbers that need about 500 rounds each for a break-in. I have a S&W 9mm EZ that has ran perfectly right out of the box. So it is just the luck of the draw whether you will have a break in period or not

It is a mechanical device. Before shooting, confirm the steps you should take with it by reading the manual. Some makers (Wilson combat is a prime example) insist that the pistol be shot as it is without being broken down for 300-500 rounds.

Remember that most pistols are not hand assembled like the Wilsons are. There will be oopsies. Much of the time, consistent with the manual, you will need to strip/wipe/lube, then shoot the heck out of it. As I recall, my 4" Shield got 700+ rounds of ball and carry ammo on the first outing, and I never had a feed issue. The advice from really knowledgable folks like Doc Roberts is to break in and then test with at least 500 rounds of carry ammo. There should be no malfs; a pistol that will not go 500 rounds without a malf is not ready for duty. My last issue pistol was a G21, and it went over 700 rounds without an issue too.

Yes, that much testing is expensive. So is a male when you need the weapon to work. I buy ammo in bulk (1K-5K at a time) to save as much as possible, but I also don't waste money on counter-productive crud like golf or a boat.

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NHI, 10-8.