Odd SW M&P issues.

[sasquatch981]

So I ran my bone stock M&P through an IPSC match today. I have standard .40 M&P with all stock fire control, and recoil springs. The load I am using is 3.5 grains of Ramshot Competition behind a 155gr Berry's Plated bullet. When I chrono the load it comes in at right around 130.

So here is what happened.

1) Gun jammed with bullet in chamber and another round partially stripped from magazine. Looked like a double feed. (Chalked it up to a double feed and moved on)

2) Next ran through stage and afteer about the 4-5th shot pulled the trigger and "click". In the heat of battle racked the slide and moved on and it worked. I though I pulled the old "chicken finger" and did not allow the trigger to reset before pulling the trigger. for the next shot. (Chalked it up to a chicken finger and moved on)

3) Finally ran the classifier and had the same thing happen as listed directly above. However this time I thought I only loaded the magazine partially full. However when I racked the slde, I noted this time, there was no round that ejected, but a new round chambered, and then finished the stage.

So here is what I am thinking. I think the recoil spring (gun only has a 200 round thorugh it) is "too strong" for the minor power factor load. It seems to have ooompf to eject the spent case, but does not always have enough slide travel to strip of the nexct round in the magazine. Does this sound reasonable, or am I missing something? That would seem to explain 2&3, but I am a little stumped on #1.

I think I may move to a 13lb recoil spring and try that. Anything else I should be thinking of?

[ChrisStock]

You're on the right track, IMO. That is a super minor load ..too light to cycle things correctly. You can either increase the load to bring the PF up around the 140 range, or contact Kenny at SpeedShooterSpecialties fora non captured guide rod and lighter spring sets to experiment with. Once you start dropping the PF like you did, it's near mandatory to do this.

[TonyT]

When I run light loads in my PO16-40 I have to go to a 14 lb recoil spring. The only semi-auto that works with factory springs and very light loads are the CZ-40's.

[revchuck]

Dang - I run a higher PF in my M&P 9!

[Dave Gundry]

I run my 9 right at 125, which supposedly has the same recoil spring as the 40's out of the box...

I have seen a few M&P's with extraction issues - i.e. spent case staying in the chamber, resulting in either a double feed or the shooter having to send the slide home and rack it again to pull the spent case out. Not sure what has caused it - the guns I've seen do it look fine - only idea is a weak extractor spring...

[DougCarden]

Quick and dirty way to see if the load is too light.......load one round and see if it will lock back. If it wont do it 5 times in a row, increase powder until really dirty gun will lock back at least 5 times.....

Something to try anyway....LOL

DougC

[sperman]

So I ran my bone stock M&P through an IPSC match today. I have standard .40 M&P with all stock fire control, and recoil springs. The load I am using is 3.5 grains of Ramshot Competition behind a 155gr Berry's Plated bullet. When I chrono the load it comes in at right around 130.

So here is what happened.

1) Gun jammed with bullet in chamber and another round partially stripped from magazine. Looked like a double feed. (Chalked it up to a double feed and moved on)

2) Next ran through stage and afteer about the 4-5th shot pulled the trigger and "click". In the heat of battle racked the slide and moved on and it worked. I though I pulled the old "chicken finger" and did not allow the trigger to reset before pulling the trigger. for the next shot. (Chalked it up to a chicken finger and moved on)

3) Finally ran the classifier and had the same thing happen as listed directly above. However this time I thought I only loaded the magazine partially full. However when I racked the slde, I noted this time, there was no round that ejected, but a new round chambered, and then finished the stage.

So here is what I am thinking. I think the recoil spring (gun only has a 200 round thorugh it) is "too strong" for the minor power factor load. It seems to have ooompf to eject the spent case, but does not always have enough slide travel to strip of the nexct round in the magazine. Does this sound reasonable, or am I missing something? That would seem to explain 2&3, but I am a little stumped on #1.

I think I may move to a 13lb recoil spring and try that. Anything else I should be thinking of?

When I went to a 13 lb. recoil spring on my M&P 9L it wouldn't always go fully into battery. I went back to the 15 lb. and haven't had a problem since. Just something to be aware of if you go to the lighter spring.

[bompa]

Use a 14lb spring with the Wolff guide rod in the 9mm with no problems at all..Load is

a 147gr LRN with 3.2 gr Bullseye and it is more accurate than this old shooter is capable of

holding..

[Throwin Lead]

Quick and dirty way to see if the load is too light.......load one round and see if it will lock back. If it wont do it 5 times in a row, increase powder until really dirty gun will lock back at least 5 times.....

Something to try anyway....LOL

DougC

+ 1 Great advice!

I shoot a M&P 40 in production and found that any load less than 135 PF has had chambering/stove pipe, sluggish slide or won't go to slide lock issues regardless of spring weight - from factory spring to a 13#. YMMV

Mike

[stiblaster]

I had a problem with my M&P 9mm failing to extract causing jams like you mentioned. I was told by one of the Team S&W guys that a few of these guns got Melonite overspray in the chambers causing the chamber to be a little rough. I polished my chamber and the problem went away.

[dcarter]

I run 147gr Winchester. I swapped out the stock recoil spring with a 13lb not too long after I started using it. I honestly don't know how many rounds I have put through it in the past year and a half but it's ALOT. I have had exactly 2 malfunctions, both my fault. The only real issues I've heard of have been due to broken strikers. I carry an extra just in case, but have never had one myself. I would try a lighter recoil spring and go from there.

[mike cyrwus]

a ismi 13# and maybe a slightly hotter load should do the trick

[Boats]

Mine out of the box had a "sticky" extractor. Probably some of the finsh go on it. Clue was when ejecting a live chambered round the extractror would not let it go everytime.

Boats