smith and wesson M&P 40 cal jamming.

nguynu2401 · March 19, 2009, 09:10 PM

I just purchased a new smith and wesson m&p40. I did my home work and S&M seems liek they have put out a perfect weapon. However, my first two boxes of ammo was a little disconserting, 20 or so of them jammed, the slide would not make the full cycle, the spend casing ejected fine, but the unfired cartridge did not seat in the barrell full, the bvreack stayed open almost 1/4 of an inch, i pull the slide back, just enough to take off the tefnsion and the cartridge would come up fully, It seems that there isn't enough spring in the mag, but it happens to both of them. I shoot on a regular basis, I am in federal law enforcement, limp wristing it is not a problem. Any help would be great,, is this weapon finiky with ammo? thanks for the help if any one has any.

ar15chase · March 19, 2009, 09:14 PM

Mine is "finicky" It seems to prefer Winchester white box. The Remington always fail to eject all the way. As for Defense loads everything I have shot worked good.

golfnutrlv · March 19, 2009, 09:15 PM

Based on my own experience, that is not normal. I have not had one malfunction in my M&P after well over 8000 rounds.

Could be the mag spring like you mentioned. Could also be an issue with the feed ramp (maybe).

Mine has fed every kind of ammo I have tried from cheap to premium without a single hitch. I would have it looked at. Just does not sound normal. As far as I know, there is no "Break In" period like other semi autos have. Anyway, S&W ought to be willing to help!

nguynu2401 · March 19, 2009, 09:28 PM

I went back to the gun smith where purchased and purchased another box of ammunition, different manufacturer,grain, everything, have not shot them yet, the gunsmith for the most part couldn't believe it, and wanted to shoot it in the coming days, thanks for the fast responce all,

gglass · March 19, 2009, 09:48 PM

I can only say that the M&P's can be a little tight out of the box and should be cleaned lock, stock and barrel then lubed before hitting the range. If it is not a clean & lube issue, you may want to check for a burr in the chamber.

I own four M&P's that have been flawless with thousands of rounds between them.

M&P40
M&P357
M&P9c
M&P9 Pro Series

vox rationis · March 19, 2009, 10:14 PM

Did you clean it of the packing grease before you shot it? An M&P ought to run as well as an HK, Glock, Sig, etc. out of the box. Call S&W and send it in cause there's something wrong with that sucker.

nguynu2401 · March 19, 2009, 10:18 PM

I did not clean it at all, the gun smith has been in the area for over 40 years, he reported that he cleaned it prior to me picking up, However i will be cleaning befor i hit the range, as far as a burr anywhere on the weapon, it is 100% perfect/flawless.

PinkFlamingo · March 19, 2009, 11:26 PM

I have about 3000 rounds through mine, fired in below zero tempurature, indoors, hot days, after carrying for a week, whatever.

The first 150 rounds had a few malfunctions. I remember a couple failures to feed, the round sticking halfway into the chamber.

After that first 150, I've had not a single hiccup.

I've fired cci blazer, blazer brass, winchester white box 180 and 165, doubletap 200 grain lead, 155-180 hydrashock

March 19, 2009, 09:10 PM	#1
nguynu2401 Member Join Date: March 19, 2009 Location: New York Posts: 22	smith and wesson M&P 40 cal jamming. I just purchased a new smith and wesson m&p40. I did my home work and S&M seems liek they have put out a perfect weapon. However, my first two boxes of ammo was a little disconserting, 20 or so of them jammed, the slide would not make the full cycle, the spend casing ejected fine, but the unfired cartridge did not seat in the barrell full, the bvreack stayed open almost 1/4 of an inch, i pull the slide back, just enough to take off the tefnsion and the cartridge would come up fully, It seems that there isn't enough spring in the mag, but it happens to both of them. I shoot on a regular basis, I am in federal law enforcement, limp wristing it is not a problem. Any help would be great,, is this weapon finiky with ammo? thanks for the help if any one has any.

March 19, 2009, 09:48 PM	#5
gglass Senior Member Join Date: November 28, 2008 Location: Indiana Posts: 638	I can only say that the M&P's can be a little tight out of the box and should be cleaned lock, stock and barrel then lubed before hitting the range. If it is not a clean & lube issue, you may want to check for a burr in the chamber. I own four M&P's that have been flawless with thousands of rounds between them. M&P40 M&P357 M&P9c M&P9 Pro Series __________________ "...shall not be infringed." (Must be 18. Void where prohibited. Some restrictions may apply. Not available in all states).

March 19, 2009, 09:14 PM	#2
ar15chase Senior Member Join Date: February 20, 2009 Location: Shallowater, Texas Posts: 444	Mine is "finicky" It seems to prefer Winchester white box. The Remington always fail to eject all the way. As for Defense loads everything I have shot worked good.

March 19, 2009, 09:15 PM	#3
golfnutrlv Senior Member Join Date: November 5, 2008 Location: Spokane, WA Posts: 1,347	Based on my own experience, that is not normal. I have not had one malfunction in my M&P after well over 8000 rounds. Could be the mag spring like you mentioned. Could also be an issue with the feed ramp (maybe). Mine has fed every kind of ammo I have tried from cheap to premium without a single hitch. I would have it looked at. Just does not sound normal. As far as I know, there is no "Break In" period like other semi autos have. Anyway, S&W ought to be willing to help!

March 19, 2009, 09:28 PM	#4
nguynu2401 Member Join Date: March 19, 2009 Location: New York Posts: 22	I went back to the gun smith where purchased and purchased another box of ammunition, different manufacturer,grain, everything, have not shot them yet, the gunsmith for the most part couldn't believe it, and wanted to shoot it in the coming days, thanks for the fast responce all,

March 19, 2009, 10:14 PM	#6
vox rationis Senior Member Join Date: April 15, 2007 Posts: 1,855	Did you clean it of the packing grease before you shot it? An M&P ought to run as well as an HK, Glock, Sig, etc. out of the box. Call S&W and send it in cause there's something wrong with that sucker.

March 19, 2009, 10:18 PM	#7
nguynu2401 Member Join Date: March 19, 2009 Location: New York Posts: 22	I did not clean it at all, the gun smith has been in the area for over 40 years, he reported that he cleaned it prior to me picking up, However i will be cleaning befor i hit the range, as far as a burr anywhere on the weapon, it is 100% perfect/flawless.

March 19, 2009, 11:26 PM	#8
PinkFlamingo Junior Member Join Date: November 4, 2008 Posts: 3	I have about 3000 rounds through mine, fired in below zero tempurature, indoors, hot days, after carrying for a week, whatever. The first 150 rounds had a few malfunctions. I remember a couple failures to feed, the round sticking halfway into the chamber. After that first 150, I've had not a single hiccup. I've fired cci blazer, blazer brass, winchester white box 180 and 165, doubletap 200 grain lead, 155-180 hydrashock