[snscott]

I just got in the ISMI 20# recoil spring and SS guiderod from SpeedShooters so I took my M&P 40 out for another spin at the range.



Extremely disturbing results

:



I was shooting with the mag short loaded to 10 rounds, using Winchester Value Pack ammo.



At around the third or fourth shot, the magazine started ejecting on it's own without chambering the next round. I had to shove the mag back in and rack the slide to fire the next shot. Every subsequent shot did the exact same thing. If I shot one-handed, the mag literally popped out to the floor. Also got a couple of stovepipes. If I loaded ONE round, it would fire and the mag would not eject, but the slide would not lock back either.



Ok, so it would have been easy to blame the new guide rod and spring, so I switched back to the stock recoil spring and rod and at the same time switched to the second magazine. This did not help because it continued to do the same thing. So, just as an extra test, I tried running a mag full of Federal Hydrashocks through it and the same thing happened. The first two or three rounds would fire properly but from that point on, each shot resulted in the mag popping out on it's own.



I took extreme care to watch my grip and hand placement to make sure I was no where near the mag release button or slide release either.



Brought it home and field stripped it for cleaning and inspection and everything looks ok and seems to work ok when just looking at it and working the parts by hand. Nothing made me think "Hmmm, that does not look right or that does not feel right".



Any suggestions, or it is just finally time to send this lemon back to S&W?

 

[matt7184]

You have one of the lemons. It would be helpful to know the beginning of your SN just for future reference. I haven't heard of this very often.



The first M&P40 I shot did this (I believe it was an MPA). A few others I have heard about have sent it to S&W and the whole frame was replaced.

 

[Jester]

I'd make a call to smith, and get a return label Right away returning the mags also.

 

[snscott]

Serial number starts with MPB

 

[snscott]

So you guys don't think the replacement recoil spring had anything to do with this?

 

[Jester]

I doubt it, I run the SSS guide rod with 15lb spring and have no problems.

 

[matt7184]

It's not the springs, it's a frame/mag catch issue. Send it to Smith and they will make it right.

 

[snscott]

I am sending it back to S&W.



Just an FYI for future reference. They don't send you a shipping label. (Which is good, because it means you don't have to wait on them to do that before you send it back)



If you email them, they respond with an email containing a Word document form letter with a return number and instructions on how to fill out the FEDEX shipping label. They tell you to ship it Standard Overnight and to mark the box for "bill to recipient".



And, I just discovered that you have to take it to an actual FEDEX shipping facility. You can not ship firearms from a FedEx/Kinkos unless you have an FFL, even if you are shipping it back to the manufacturor. (Which is just silly, but dems da rulez)

 

[YukonGlocker]

Keep us informed on what happens.



Yes, shipping guns can get frustrating.

 

[Jester]

I am sending it back to S&W.



Just an FYI for future reference. They don't send you a shipping label. (Which is good, because it means you don't have to wait on them to do that before you send it back)



If you email them, they respond with an email containing a Word document form letter with a return number and instructions on how to fill out the FEDEX shipping label. They tell you to ship it Standard Overnight and to mark the box for "bill to recipient".

They do send a shipping label if you call them. I have had this happen, Its nice to know they will email you the stuff also. If you get the UPS label you can actually take it to the terminal and they will package it for you, its right in smiths instructions.

 

[snscott]

Ok, my baby went out today.

Got it to the local FEDEX office at the airport at around noon.



Funny thing is I left one end of the FEDEX box open as I got to the counter so they could inspect the firearm. You know, make sure it was unloaded, whatever. They asked me to close up the box and said they didn't need to inspect it.

 

[Captain Ray]

Isn't a 20lb recoil spring a bit heavy for the M&P? I am surprised the thing would cycle at all?!



Raymond

 

[snscott]

Actually, I could not tell much difference when I worked the slide manually. Did seem to reduce the felt recoil just a bit. Nothing dramatic, nothing to make me say "Wow!", but somewhat of a difference. It was a real bear to get it into the gun initially, though. Had to work it through some compressions outside the gun first.



But then I did not have a chance to really get into it and get a good feel for it before the mags started popping out of their own accord and I switched back to the stock spring.



FWIW, I replaced the stock spring (18#?) on my XD-9 with a 22# and it is noticeably harder to rack the slide, and I notice the recoil difference more when shooting it. Still, even with that, it is not different enough to make me say "Wow!".

 

[Captain Ray]

I also use a 22 lb spring in my XD 9... It is a bit of a pull to rack the slide, but it does perform very well. I have not changed out guide springs in my M&P though.. I would think going from a 14 lb spring to a 20 lb spring might be a bit much for this pistol.



The thing is.. and I am sure you already know this.. is that putting in a heavier spring slows the recoil.. which may make it a little friendlier on your hands.. but it slows the cycle of the gun.. which means less muzzle velocity, and increases the likelihood for a malfunction. I suppose it is a matter of finding that balance...



Raymond

 

[Jester]

The thing is.. and I am sure you already know this.. is that putting in a heavier spring slows the recoil.. which may make it a little friendlier on your hands.. but it slows the cycle of the gun.. which means less muzzle velocity, and increases the likelihood for a malfunction. I suppose it is a matter of finding that balance...



Raymond

Actually having the heavier spring will add velocity, your keeping the the pistol in battery longer allowing for a more complete burn, a more stable launching platform is a byproduct.



It does add time to the follow up shots for those who compete, you state that above by slowing the cycle (keeping it in battery longer), depending on what loads your shooting in your pistol.

 

[snscott]

The stock spring in the MP40 must be more than 14#. Either that, or the 20# ISMI spring is not really 20#, because I could not tell any significant difference in resistance when I racked the slide and since I switched back to the stock spring during the same range visit, I was able to try them out "side by side", sort of. The XD-9, going from 18# to 22# IS significantly noticeable.



But, as you say, that is the nice thing about the after-market SS guide rod is that you can cheaply and easily swap out and try different weight springs to see their effect on your handling of the gun.



Not sure how a heavier recoil spring would reduce muzzle velocity, though? Would seem to me that the bullet would have something stouter to push against and therefore it would increase velocity if it had any effect at all. But I'm certainly no physics expert, either.

 

[toocool]

I am sending it back to S&W.



Just an FYI for future reference. They don't send you a shipping label. (Which is good, because it means you don't have to wait on them to do that before you send it back)



If you email them, they respond with an email containing a Word document form letter with a return number and instructions on how to fill out the FEDEX shipping label. They tell you to ship it Standard Overnight and to mark the box for "bill to recipient".



And, I just discovered that you have to take it to an actual FEDEX shipping facility. You can not ship firearms from a FedEx/Kinkos unless you have an FFL, even if you are shipping it back to the manufacturor. (Which is just silly, but dems da rulez)

That's strange...I shipped a Sig P220 to Robar using a Fed-Ex/Kinko's with no problem. The lady at Kinko's didn't think she could do it, but she called a district manager or something and he said "of course it's OK to ship it..." so they shipped it with no problem.

 

[snscott]

Got an email about my MP40 from S&W today where they said:

Our current turn around time is approximately 3 weeks

 

[matt7184]

That's quite a bit longer than it was a year ago. Still about average for a manufacturer though.



Is this for all work or your particular gun?



Regardless I hope they can get it down to the 1-2 week frame.

 

[akr]

snscott-----



Mine is a B. The next two numbers aren't 56, are they?