My M&P9

[MarkCO]

In my tinkering and playing with 2 stock barrels and 2 different KKM barrels and a Storm Lake and having a lot of experience with match barrels and fitting barrels into Glocks, I think it is a combination of tolerance and geometry of the longer barrels. The 9L and 9Pro have an increased diameter at the end of the barrel and it is not what I would call tight. It is possible that the design was attempting to have "Glock" reliability by having a loose fit in the lock-up and hood beleiving that the increased OD of the barrel near the muzzle would yeild acceptable accuracy. From my perspective, they are chasing accuracy by changing things that won't improve it. The fit at the chamber end of the barrel needs to be tightened up considerably in order to have any benefit. The newer run of barrels still has sloppy lock-up. You can actually press on the slide and it will come out of battery! With the SL and KKM, not so. The most wear on my stock barrel is at the increased diameter ring.

The aftermarket barrels have more material since they are straight barrels instead of the smaller OD of the stock barrels, so they weigh a tad more too.

Don't get me wrong, I really like my M&P and I will stick with it, but it is frustrating to spend the money on a pistol and be almost required to buy an aftermarket barrel.

[Art Yeo]

Thanks for the analysis. You'd think that S&W should know these after manufacturing semi-autos for decades.

When I looked at my original barrel, I am seeing the most wear on top of the breach front where the barrel impacts forward. The edge is no longer a straight 90 degree edge but slightly bevelled.

Are you guys seeing this in your old stock barrel (not the new design)?

[Art Yeo]

Hmm... That would seem like premature unlocking before the bullet has left the barrel or just as it is leaving. But it's really hard to believe they would have it that close, the barrel length just isn't that much different. I was told by a pretty good M&P smith that the very early barrels (Pro and L) are kind of iffy on tolerances. My money is that they still are.

Interesting thot ....

1. Discharge
   
2. Barrel unlocks
   
3. Bullets leaves … and went hay-wire
   

If that's the case, the gun is not considered functional because it's a loose canon. Surely, the design team has ways to use high-speed infrared photography to understand what the heck is going on in there.

[MattYvip]

Maybe I got lucky because I have an M&P (still bone stock) and I have nothing but good things to say about it... at 25 yards I've put an entire magazine in the A zone (the head A zone that is) granted I was taking my time to see where the zero was. I've put several hundred rounds through it (I doubt I'm up to a thousand yet) and I've been nothing but impressed. Not trying to discout everyones experience by any means, I guess I'm just suprised because of my great experiences with my personal M&P. Like I said, Maybe I got lucky.

Edited August 24, 2012 by MattYvip

[MarkCO]

Maybe I got lucky because I have an M&P (still bone stock) and I have nothing but good things to say about it... at 25 yards I've put an entire magazine in the A zone (the head A zone that is) granted I was taking my time to see where the zero was. I've put several hundred rounds through it (I doubt I'm up to a thousand yet) and I've been nothing but impressed. Not trying to discout everyones experience by any means, I guess I'm just suprised because of my great experiences with my personal M&P. Like I said, Maybe I got lucky.

Matt, I was happy at the point you are at too. I think it was over 1K that the accuracy really went to patterns instead of groups. And, if you don't have a longslide (L or Pro) is will probably remain accurate.

[Art Yeo]

The other thing I noticed was that twist-rate of the m&p9 is a lot slower than competiting products in the market such the CZ75 and Beretta92 (both around 1:10) while the m&p9 is 1:18.75.

That seems to indicate the m&p9 favoring lighter bullets?

Edited August 24, 2012 by Art Yeo

[MarkCO]

That seems to indicate the m&p9 favoring lighter bullets?

That bore out in the affirmative for me and my M&P (that rhymes )

[Seth]

The telling moment for me was with the gun in a vice and a bore sighter laser pointed at the wall I slowly racked the slide. There was no time between the initial movement of the slide and the tilt of the barrel.

[Shadowrider]

Hmm... That would seem like premature unlocking before the bullet has left the barrel or just as it is leaving. But it's really hard to believe they would have it that close, the barrel length just isn't that much different. I was told by a pretty good M&P smith that the very early barrels (Pro and L) are kind of iffy on tolerances. My money is that they still are.

Interesting thot ....

1. Discharge
   
2. Barrel unlocks
   
3. Bullets leaves … and went hay-wire
   

If that's the case, the gun is not considered functional because it's a loose canon. Surely, the design team has ways to use high-speed infrared photography to understand what the heck is going on in there.

Been thinking about this for a bit and I'm sure they have used something to confirm that lockup is still there until the bullet exits and they have some "safety factor" engineered into it. That's why I stated I had a hard time believing it would be that close. I suspect it's something along the lines of what MarkCO is saying in that the slide/barrel fit tolerance is pretty loose for reliability.

I know that mine will hit a steel USPSA target at 50 yards all day long with my 147 lead bullet 130PF loads, but it is all over the target. A, C and D zone with no apparent preference, looks like a shotgun pattern.

[Art Yeo]

The telling moment for me was with the gun in a vice and a bore sighter laser pointed at the wall I slowly racked the slide. There was no time between the initial movement of the slide and the tilt of the barrel.

That's a nice mechanism to see when the bore gets shifted.

But, how did you hook up a laser light inside the barrel?

[retarmyaviator]

Maybe I got lucky because I have an M&P (still bone stock) and I have nothing but good things to say about it... at 25 yards I've put an entire magazine in the A zone (the head A zone that is) granted I was taking my time to see where the zero was. I've put several hundred rounds through it (I doubt I'm up to a thousand yet) and I've been nothing but impressed. Not trying to discout everyones experience by any means, I guess I'm just suprised because of my great experiences with my personal M&P. Like I said, Maybe I got lucky.

I'm in the same boat. 9mm FS shoots just fine, it has somewhere between 2500-3000 rounds through it. 9mm Pro doing well with approximately 1500 rounds fired. I have a M&P 45 FS also, all three are used in matches with no problems.

[Art Yeo]

Here are some pictures for you guys ...

Using 115gr FMJ for the 9mm guns and 230gr FMJ for the 45ACP guns:

At 25 ft,

M&P9 (N.B. Ring on plate is around 5.5")

Beretta 92A1

Kimber 1911 and M&P45

At 50ft,

M&P9 (N.B. Ring on plate is around 5.5")

Beretta 92A1

Edited August 24, 2012 by Art Yeo

[mcracco]

Art: Nice job. Very telling...

[Art Yeo]

Just curious, could the recoil spring be too weak to bring the barrel back into the correct lock-up?

Anyone replace their recoil spring and still have accuracy issues?

Edited August 25, 2012 by Art Yeo

[soterik]

Those plates look very similar to my results

So 9mm M&Ps aren't as accurate as some other pistols.

Is that the consensus?

I guess we can try the Storm Lake fitted barrel when they come available. Other than that, just shoot it within it's limits.

Edited August 25, 2012 by soterik

[Seth]

Its limits prohibited me from using it confidently in a match. I can't HOPE that match directors don't use any targets beyond 12 yards.

[mcracco]

Its limits prohibited me from using it confidently in a match. I can't HOPE that match directors don't use any targets beyond 12 yards.

Since this isn't bullseye shooting...will the inaccuracy be in your favor or against it? I know my 45 Gold Cup and 45 M&P are more accurate but my go to match gun is still my 9 Pro M&P. I am not yet turning in Master scores with any of those guns so my focus is on me and not the hardware.

But now you guys got me going. Next week I will do the paper plate thing with the 9mm.

Edited August 25, 2012 by mcracco

[Greg in VA]

I tried the paper plate thing with my M&P Pro 9mm. But my shooting was at 10yds, 25yds and 50yds. My results were that I needed a bigger paper plate. At 10yds 3-4" groups, at 25yds 8-10" groups, at 50yds I had to use a D-1 Action Pistol target just to get the group to print on paper, the groups were about 18-24". I shot 115gr Lead, Jacketed, round nose and hollow point, I shot 124gr lead, Jacketed, round nose and hollow point, I shot 135 grain jacketed round nose and hollow point, I shot 145 gr lead semi wadcutters, I shot 147gr jacketed round nose and hollow point. My Springfield 5.25 in 9mm shoots groups that measure just under 3" at 50 yds.....go figure.

Greg

[Art Yeo]

Just curious, could the recoil spring be too weak to bring the barrel back into the correct lock-up?

Anyone replace their recoil spring and still have accuracy issues?

Could someone comment on this, please? Could it be this simple?

[Seth]

Nope. I tried a 17# spring and it made no difference.

[Art Yeo]

Nope. I tried a 17# spring and it made no difference.

Thanks for responding.

For my M&P9. when I apply downward pressure on the slide or the tip of the barrel, they can move with reasonable effort.

Is it supposed to be this loose when barrel is in battery? Is yours this way, too, after the new recoil spring?

This got me more curious and I went to check my accurate M&P45 and it is doing the same.

Tried the same test on the Beretta and I could not move anything no matter how hard I tried. Same with any of my 1911's.

[Shadowrider]

Nope. I tried a 17# spring and it made no difference.

Thanks for responding.

For my M&P9. when I apply downward pressure on the slide or the tip of the barrel, they can move with reasonable effort.

Is it supposed to be this loose when barrel is in battery? Is yours this way, too, after the new recoil spring?

This got me more curious and I went to check my accurate M&P45 and it is doing the same.

Tried the same test on the Beretta and I could not move anything no matter how hard I tried. Same with any of my 1911's.

Okay I just checked both my 9 Pro and 45. When I press on the slide it will move downward, but the barrel goes with it. It pretty much HAS TO because the lockup is in contact with the slide on the bottom of the barrel. I can get movement of the slide and barrel to the frame but the barrel and slide move together being locked up. Mine have clearance between the barrel and slide on the top of the barrel (at the straight up 12:00 o'clock position).

Edit to add: I just compared something else.

When I slowly move the slide to the rear on my 45 the barrel goes with it for about .080" before starting to unlock with the slide just like it should. My 9 Pro starts unlocking with the slide immediately from the looks of it. If it travels rearward with the slide it's not enough for me to see. Interesting...

Edited August 26, 2012 by Shadowrider

[mjohn]

The telling moment for me was with the gun in a vice and a bore sighter laser pointed at the wall I slowly racked the slide. There was no time between the initial movement of the slide and the tilt of the barrel.

Could you please explain what your comment "There was no time between the initial movement of the slide and the tilt of the barrel," means? Is that a good or bad thing and why?

Thanks

[Seth]

The telling moment for me was with the gun in a vice and a bore sighter laser pointed at the wall I slowly racked the slide. There was no time between the initial movement of the slide and the tilt of the barrel.

Could you please explain what your comment "There was no time between the initial movement of the slide and the tilt of the barrel," means? Is that a good or bad thing and why?

Thanks

Sure. The bullet has NOT left the barrel before the gun drops out of battery. Therefore the gun cannot shoot in a straight line by my hypothesis.

[mcracco]

I checked the lockup on:

45FS with OEM barrel

9FS with OEM barrel

9FS with SL barrel

9PRO with OEM barrel

9PRO with SL barrel

In all the above configurations I can move the slide back about .100" before the barrel starts to drop. Note that I am not complaining about accuracy with the 9's so I may be strengthening the early unlock/poor accuracy theory.

The other thing worth mentioning is both my 9 barrels are 2011 production and they do not have the ring in front of the chamber. Rather the chamber is longer and squared off and there is a step where it mates with slide. (thought someone posted a pic of the 2 designs side by side but can't find it) The 2 SL barrels (unknown production) have the shorter looking chambers with the ring.

Again, I'll try to do the pie plate thing next week with OEM and SL barrels in the Pro as well as the 45. Should be interesting.