MP 9 Shield EZ M2.0 doesn't like Win 115 gr FMJ Ammo

[Wessen Smith]

I have a new (3mos) M&P9 Shield M2.0 that doesn't seem to like factory Win 115 grain FMJ Ammo. I've had numerous jams attempting to fire the ammo. The cartridges seem to be sticking near the top of the ramp on the rear of the barrel.
I checked the SAAMI spec for 9 mm ammo, and it calls for a COL of 1.168 in. The Win factory ammo that I have had problems with has a COL of 1.153 in.

I did some reloads with both 115 gr FMJ and 115 gr JHP beginning at the SAAMI 1.168 COL, and taking them progressively shorter until they fed smoothly. They (both FMJ and JHP) fed smoothly at 1.108 COL.
Is it unusual for the MP9 Shield M2.0 EZ to choke on factory ammo? Does anybody see a problem with the 1.108 COL that I finally got smooth feeding with? Does anybody see a problem with my increasing bullet seating depth on factory ammo to 1.108 COL to achieve smooth feeding with that ammo? Finally, does anybody believe I should be concerned about any or all of this?
Thanks for your advice and comments.

 

[rockster`]

I have a new (3mos) M&P9 Shield M2.0 that doesn't seem to like factory Win 115 grain FMJ Ammo. I've had numerous jams attempting to fire the ammo. The cartridges seem to be sticking near the top of the ramp on the rear of the barrel.

I checked the SAAMI spec for 9 mm ammo, and it calls for a COL of 1.168 in. The Win factory ammo that I have had problems with has a COL of 1.153 in.



I did some reloads with both 115 gr FMJ and 115 gr JHP beginning at the SAAMI 1.168 COL, and taking them progressively shorter until they fed smoothly. They (both FMJ and JHP) fed smoothly at 1.108 COL.

Is it unusual for the MP9 Shield M2.0 EZ to choke on factory ammo? Does anybody see a problem with the 1.108 COL that I finally got smooth feeding with? Does anybody see a problem with my increasing bullet seating depth on factory ammo to 1.108 COL to achieve smooth feeding with that ammo? Finally, does anybody believe I should be concerned about any or all of this?

Thanks for your advice and comments.

You say it doesn't like Win 115gr, does it reliably feed any other ammo?

Sent from my Pixel 3 using Tapatalk

 

[Ranger17]

I’ve no Winchester handgun rounds but my EZ has been perfect with Blazer Brass, Rem UMC and Am Eagle ammo. All 115 fmj.
Never tried reloads in any of my guns so cant speak for that, but as far as running factory ammo that is all i have owned or shot thru my various MP models. All with perfect results.

 

[Dave Lively]

Funny you should mention Winchester White Box (WWB) ammo. A couple of days ago a friend mentioned the Glock 19 he has probably put 10,000 rounds through with no problems had some failures to fire with WWB. The WWB worked in a different gun and the Glock works with all other types of ammo. Years ago I also had a Glock 19 it never failed with WWB but often the empties barely dribbled out of the gun. It seemed to loaded weakly compared to other types of ammo. Different problems but same ammo.

Yes, you can get into trouble but seating bullets deeper. When the bullet is pushed back the powder has less room to expand which increases pressure. Search for "bullet setback" and "kaboom". Back when the 40 S&W was more popular you would see posts about kabooms that were blamed on bullet setback. Usually when heavy bullets were paired with fast powder. Less likely to be an issue with a 115 grain 9mm loaded on the light side but still not recommended.

It might be seating the bullets deeper increased the pressure and resulted in the slide going all the way back and fully compressing the recoil spring instead of going back just far enough to eject the empty and pick up a new round. But I still wouldn't feel comfortable raising pressure that way.

Did the ammo have weak ejection before you seated the bullets deeper?

If you are not already gripping the gun as hard as you possibly can try that and see if it helps. You want all the recoil pushing the slide back, not pushing the whole gun back in your hand or flipping up.

 

[swsig]

In addition to Dave Lively's advice, try some more powerful ammo. WWB 115g may not be strong enough to reliably cycle a tight new slide with a stiff new recoil spring. If you can find some, I recommend Winchester NATO 124g. It's a much stouter round than your 115g. If you can't find Win NATO, get some +P JHP self-defense rounds and use those to break in your Shield. You need to find some good self-defense rounds that fire reliably and accurately anyway, so now's a good a time as any to do that. Will it be expensive? You bet. But the cost could be be much greater if you don't have a reliable and accurate self-defense round when you need one.

 

[STORMINORMAN]

Seating factory ammunition "deeper" is definitely NOT A GOOD IDEA!

 

[murphydog]

There may not be a direct, simple answer to your question.

Your Shield has several variables that 'may' be causing it to not feed slightly shorter than normal ammo. The pistol being fully "broken in" and the magazine (if it only misfeeds with one of these) are some.

It could also be this particular batch of WWB ammo, or the powder used. It's produced in the hundreds of millions and some variation in tolerances is expected.

Bottom line, I'd say stick to practice (and carry) ammo that functions 100% and I definitely second not altering the factory rounds.

 

[Dave Lively]

If you can find some, I recommend Winchester NATO 124g. It's a much stouter round than your 115g.

Speer Lawman is also loaded hotter than most other inexpensive 9mm factory ammo. Pre-2020 it was about the same price as WWB or Blazer Brass. These days you have to take what you can get but when the current panic buying starts to ease it is another option.

 

[SchemaEnigma]

I have a new (3mos) M&P9 Shield M2.0 that doesn't seem to like factory Win 115 grain FMJ Ammo. I've had numerous jams attempting to fire the ammo. The cartridges seem to be sticking near the top of the ramp on the rear of the barrel.
I checked the SAAMI spec for 9 mm ammo, and it calls for a COL of 1.168 in. The Win factory ammo that I have had problems with has a COL of 1.153 in.

I did some reloads with both 115 gr FMJ and 115 gr JHP beginning at the SAAMI 1.168 COL, and taking them progressively shorter until they fed smoothly. They (both FMJ and JHP) fed smoothly at 1.108 COL.
Is it unusual for the MP9 Shield M2.0 EZ to choke on factory ammo? Does anybody see a problem with the 1.108 COL that I finally got smooth feeding with? Does anybody see a problem with my increasing bullet seating depth on factory ammo to 1.108 COL to achieve smooth feeding with that ammo? Finally, does anybody believe I should be concerned about any or all of this?
Thanks for your advice and comments.

I had this same issue with my new 9 EZ. At first, I thought it was the ammo. It wasn't.

1. Polish the feed ramp.
2. Polish the magazines.
3. Re-test

The above worked for me.

 

[sousana]

I've found that my shields shoot best with 124 and 147 but phenomenally well with 158gr Israeli blue tip.

 

[Wessen Smith]

I had this same issue with my new 9 EZ. At first, I thought it was the ammo. It wasn't.

1. Polish the feed ramp.
2. Polish the magazines.
3. Re-test

The above worked for me.

Thanks for the suggestions. I tried your suggestions and they definitely helped. Thanks.
I was uncertain about where and how to polish the mags. I polished the ramp with a dremel tool, buffing wheel and some jewelers rouge. Any specifics on where and how to polish the mags?
Thanks again for your help.

 

[Wessen Smith]

You say it doesn't like Win 115gr, does it reliably feed any other ammo?

Sent from my Pixel 3 using Tapatalk

The Win white box 115 grain, and a Sign JHP 115 gr are the only factory bullets I've tried this far. Have'nt had any problems to date with the sigs.

 

[Wessen Smith]

Funny you should mention Winchester White Box (WWB) ammo. A couple of days ago a friend mentioned the Glock 19 he has probably put 10,000 rounds through with no problems had some failures to fire with WWB. The WWB worked in a different gun and the Glock works with all other types of ammo. Years ago I also had a Glock 19 it never failed with WWB but often the empties barely dribbled out of the gun. It seemed to loaded weakly compared to other types of ammo. Different problems but same ammo.

Yes, you can get into trouble but seating bullets deeper. When the bullet is pushed back the powder has less room to expand which increases pressure. Search for "bullet setback" and "kaboom". Back when the 40 S&W was more popular you would see posts about kabooms that were blamed on bullet setback. Usually when heavy bullets were paired with fast powder. Less likely to be an issue with a 115 grain 9mm loaded on the light side but still not recommended.

It might be seating the bullets deeper increased the pressure and resulted in the slide going all the way back and fully compressing the recoil spring instead of going back just far enough to eject the empty and pick up a new round. But I still wouldn't feel comfortable raising pressure that way.

Did the ammo have weak ejection before you seated the bullets deeper?

If you are not already gripping the gun as hard as you possibly can try that and see if it helps. You want all the recoil pushing the slide back, not pushing the whole gun back in your hand or flipping up.

Thanks for your suggestions. I think I'm gripping it pretty tight, but I'll pay special attention to that next time I shoot.

 

[CB3]

Thanks for the suggestions. I tried your suggestions and they definitely helped. Thanks.
I was uncertain about where and how to polish the mags. I polished the ramp with a dremel tool, buffing wheel and some jewelers rouge. Any specifics on where and how to polish the mags?
Thanks again for your help.

I serious doubt it is the ammo. Almost every mass manufactured gun should be able to shoot all commercial ammo. The exceptions are the tiny little pistols that have very narrow operating window RE: pressure, OAL, bullet shape etc.

Polishing the feed ramp, chamber hood and even the back end of the chamber is always helpful. Using a Dremel, apply very fine jeweler’s polish to the bullet shaped soft (cotton?) tip. You will not ruin the gun if you just polish without grinding material away.

On mags, I do two areas. Using 1,000 grit wet/dry sand paper, slightly damp, I lightly polish where the feed lips contact the cartridge case. Likewise, I’ll check the plastic follower for any burrs or roughness and very, very gently use the same paper to smooth it if necessary.

While springs are stiff on a new gun, so are the interfacing metal parts, like slide rail grooves. The stiff springs soften a little with cycling, and likewise, rough areas of interfacing metal smooth out. Thus breaking in a gun improves reliability. It feels smoother.

With the cost of ammo so high today, shooting hundreds of rounds to break it in makes less sense than ever. Before I ever shoot a new gun, I break it in with polishing, hand cycling and dry firing until I feel it smooth out. It will feel right, not new, stiff, rough.

I don’t ever have problems with shooting any ammo in a 9mm. The break-in pre-shooting process using 800 or 1000 grit paper on all interfacing surfaces except blued or finished works. Then I use grease for lubrication because it stays in place while breaking in the gun.

Your gun problem is easily fixed. It can happen slowly, expensively and in an aggravating manner that detracts from your confidence in the gun by shooting hundreds of rounds, or it can happen over a few evenings while you get to know your new gun better and break it in “rapidly”.

Good luck.

 

[SchemaEnigma]

Thanks for the suggestions. I tried your suggestions and they definitely helped. Thanks.
I was uncertain about where and how to polish the mags. I polished the ramp with a dremel tool, buffing wheel and some jewelers rouge. Any specifics on where and how to polish the mags?
Thanks again for your help.

I serious doubt it is the ammo. Almost every mass manufactured gun should be able to shoot all commercial ammo. The exceptions are the tiny little pistols that have very narrow operating window RE: pressure, OAL, bullet shape etc.

Polishing the feed ramp, chamber hood and even the back end of the chamber is always helpful. Using a Dremel, apply very fine jeweler’s polish to the bullet shaped soft (cotton?) tip. You will not ruin the gun if you just polish without grinding material away.

On mags, I do two areas. Using 1,000 grit wet/dry sand paper, slightly damp, I lightly polish where the feed lips contact the cartridge case. Likewise, I’ll check the plastic follower for any burrs or roughness and very, very gently use the same paper to smooth it if necessary.

While springs are stiff on a new gun, so are the interfacing metal parts, like slide rail grooves. The stiff springs soften a little with cycling, and likewise, rough areas of interfacing metal smooth out. Thus breaking in a gun improves reliability. It feels smoother.

With the cost of ammo so high today, shooting hundreds of rounds to break it in makes less sense than ever. Before I ever shoot a new gun, I break it in with polishing, hand cycling and dry firing until I feel it smooth out. It will feel right, not new, stiff, rough.

I don’t ever have problems with shooting any ammo in a 9mm. The break-in pre-shooting process using 800 or 1000 grit paper on all interfacing surfaces except blued or finished works. Then I use grease for lubrication because it stays in place while breaking in the gun.

Your gun problem is easily fixed. It can happen slowly, expensively and in an aggravating manner that detracts from your confidence in the gun by shooting hundreds of rounds, or it can happen over a few evenings while you get to know your new gun better and break it in “rapidly”.

Good luck.

What I did was similar, only I used Mother's Mag polish and a soft cloth on the feed ramp and a mild sharpening stone on the mag lips follower, and for good measure to smooth the inside of the magazines.

I used this stone

(which fits just right inside the mags). It's for sale on Dan's web site and also on Amazon.

 

[Wessen Smith]

Thanks again.