View Full Version : M&P 9f unlocking issue.
I have two Full size 9mm M&Ps.
I have One I use for training and shoot all the time. I purchased this pistol about a month ago. It has the serial number prefix of DVS, and the square magazine floor plate buttons.
I also have a pistol that I train very little with, and carry regularly that I've had for maybe 4 months. This pistol has a serial number prefix of DVD and has the older round floor plate button mags.
I recently reported that my pistol shot POA/POI at 25 yards with cheap practice stuff (Federal 115g champion FMJ). This was in reference to the carry pistol, and I was quite happy to find this out.
Saturday afternoon I was at my club and was working on 3x5 walkback drills with the training pistol. I noticed that I had to start holding at the bottom edge of the card to get center hits at about 10 yards. I usually "drive the dot" so this got my attention. I ran the target carrier all the way to the end of the bay (25yds) with an 8.5x11 sheet of paper as a target. I rested my pistol on the bench and started shooting 10 round groups-I wasn't even on paper using a center hold on the target after 10 rounds. Yikes. I shot 10 more using a 6 o'clock hold, and landed one (1) on the top left of the target. Double yikes. Needless to say I was quite alarmed.
Now I'm not winning any bullseye shoots anytime soon, but I was pretty certain that I could shoot a little better then that. To confirm it was the gun and not me, I loaded 5 rounds of 124+p Gold Dot and immediately shot a ~6" 25yd group on the same target using the same rest and a center hold.
Dammit.
Obviously it's unlocking early, yes?
Armed with the information I gathered here and from m4c, I prepared to fight for a prepaid shipping label from S&W. I called up customer service this morning and I talked to a lady named Pam. I explained to her, as concisely as I could, exactly what was happening. To my delight, she said she would email me a prepaid shipping label in 48 hours, and they would take a look at it. :cool:
Now I have a couple questions.
-should I clean this thing before I ship it back? I'm ~1000 rounds through the 2000 round challenge. It's filthy.
-what are they going to do to it?
I'll add updates as this progresses.
It kills me that a pistol I shot a 48 on DotTorture with at 3 yards isn't even on paper at 25.
I'm disappointed to hear about your issues.
-should I clean this thing before I ship it back? I'm ~1000 rounds through the 2000 round challenge. It's filthy. I wouldn't. Don't change anything.
-what are they going to do to it?No one knows. Want to know what they did with mine, under very similar circumstances? They shot it with WWB, said it was within spec, returned the gun (w/ test target) unmodified.
FWIW: I've noticed that excessively weak recoil springs seem to exacerbate the issue, probably because it unlocks that much faster if there is too little spring tension. Or perhaps it's not fully returning to battery (slightly unlocked). How worn is your recoil spring?
FWIW: I've noticed that excessively weak recoil springs seem to exacerbate the issue, probably because it unlocks that much faster if there is too little spring tension. Or perhaps it's not fully returning to battery (slightly unlocked). How worn is your recoil spring?
Hardly worn at all. I bought this gun NIB and have only shot maybe a case through it.
Kyle Reese
06-06-2011, 10:38 AM
Sorry to hear you're having issues. I had the same thing happen with my FS 9mm guns, and I ended up divesting myself from the M&P platform completely as a result.
I realized that it was the gun when I shot ghastly at 25 yds with the M&P 9, and when I borrowed a Glock 17 from another Staff member and proceeded to clean the rack.
The premature unlocking is a real issue with the FS 9mm guns, and I hope Smith addresses it.
Sorry to hear you're having issues. I had the same thing happen with my FS 9mm guns, and I ended up divesting myself from the M&P platform completely as a result.
And I JUST switched to the M&P. Haha.
What are you shooting now?
ToddG
06-06-2011, 02:36 PM
-should I clean this thing before I ship it back? I'm ~1000 rounds through the 2000 round challenge. It's filthy.
Yes. If you don't, many companies will simply blame the lack of cleaning/lube as the cause of any and all problems.
I'd send along two test targets, one shooting the 124gr +p at 25yd and one shooting the 115gr standard pressure at the same distance. Use a big enough target that the 115gr rounds will hit paper using the same POA as the 124+p.
-what are they going to do to it?
Anyone's guess. They might test fire it and say it works fine for them. They might test fire it and fix/replace something. They might take your word for it and replace the barrel, slide, or both right from the start.
Thanks Todd.
I really hope they fix this thing.
Yes. If you don't, many companies will simply blame the lack of cleaning/lube as the cause of any and all problems. Maybe that's why they sent my gun back - unchanged? If so, I'm pretty pissed.
Has anybody tried simply swapping barrels (either with a new replacement or with a barrel from a known non-problematic gun) to see if that fixes the issue on the problem guns? Not that you should have to, but I was wondering if the issue is with the occasional barrel that's out of spec, or tolerance stacking.
I'm gonna switch the barrel from my good gun into the bad one tonight while I'm at the range. I'll let you know what happens.
ToddG
06-07-2011, 10:29 AM
Has anybody tried simply swapping barrels (either with a new replacement or with a barrel from a known non-problematic gun) to see if that fixes the issue on the problem guns?
Yes, it does. Smith made a short run of special barrels for Ernest Langdon that solved the accuracy issues every time. I actually have one of those barrels and it is laser accurate.
I've also seen where simply swapping around factory barrels in a gun makes the problem go away.
John Ralston
06-07-2011, 11:11 AM
I'm gonna switch the barrel from my good gun into the bad one tonight while I'm at the range. I'll let you know what happens.
If that fixes it, make sure you put a note in with the gun and call CS and tell them to add the info to your return authorization file.
It would at least lessen the chances of getting it back as is, and having them tell you it worked fine with WWB.
If that fixes it, make sure you put a note in with the gun and call CS and tell them to add the info to your return authorization file.
It would at least lessen the chances of getting it back as is, and having them tell you it worked fine with WWB.
I certainly will. Thanks John.
Yes, it does. Smith made a short run of special barrels for Ernest Langdon that solved the accuracy issues every time. I actually have one of those barrels and it is laser accurate.
I've also seen where simply swapping around factory barrels in a gun makes the problem go away.
How much?! ;)
DannyZRC
06-07-2011, 12:11 PM
there is also, of course, the apex barrel that's coming.
(I elected to avoid this entirely and bought a 40. Short and Weak kool-aid is kinda tasty)
ToddG
06-08-2011, 02:44 AM
there is also, of course, the apex barrel that's coming.
Buying an aftermarket barrel because you want match grade accuracy from a service grade handgun is one thing. Spending cash on a NIB gun to fix a problem that shouldn't exist so you can be confident the bullets go in the same direction as the sights is something else.
DannyZRC
06-08-2011, 03:42 AM
the world as it is, the world as it should be.
just sayin'
I didn't get to the range last night. I'll be there when they open today. Updates shortly.
there is also, of course, the apex barrel that's coming.
(I elected to avoid this entirely and bought a 40. Short and Weak kool-aid is kinda tasty)
As cool as that is, I'd never be able to shoot up to that barrel. It would be a frivolous use of 300 dollars for me.
And I'm not about to spend 300 additional dollars to get a 500 dollar gun to do what's it's supposed to do in the first place.
Also, my use of the $300 figure is a guess of course.
Just got home from the range.
-using the barrel from the "good" gun did nothing to improve grouping from the "bad" gun.
-Federal American Eagle 124 grain and Federal Champion 115 grain are both wildly inaccurate out of the "bad" gun, and shoot essentially to point of aim in the "good" gun.
-Speer Gold Dot 124+p is very accurate out of both guns.
I'll be calling FedEx for a pick up this afternoon. Wish me luck.
http://tapatalk.com/mu/a6cd0870-d7c9-9f3b.jpg
9 rounds of Gold Dot from the "bad" gun @ 25 yards.
http://tapatalk.com/mu/a6cd0870-d805-5088.jpg
9 rounds of American Eagle from
The "bad" gun @ 25 yards.
Kyle Reese
06-08-2011, 03:16 PM
Just got home from the range.
-using the barrel from the "good" gun did nothing to improve grouping from the "bad" gun.
-Federal American Eagle 124 grain and Federal Champion 115 grain are both wildly inaccurate out of the "bad" gun, and shoot essentially to point of aim in the "good" gun.
-Speer Gold Dot 124+p is very accurate out of both guns.
I'll be calling FedEx for a pick up this afternoon. Wish me luck.
Call S&W. They should issue you a call tag for return.
Call S&W. They should issue you a call tag for return.
Done.
pointfiveoh
06-09-2011, 10:22 AM
So when I buy an M&P 9f the first thing I should do when I shoot it is bench it at 25 to see if it works properly?
So when I buy an M&P 9f the first thing I should do when I shoot it is bench it at 25 to see if it works properly?
If you intend to practice at those ranges and are worried about the subject at hand, yes. My gun shoots fine out to about 10 yards or so then it falls on it's face.
ToddG
06-09-2011, 12:14 PM
So when I buy an M&P 9f the first thing I should do when I shoot it is bench it at 25 to see if it works properly?
I would:
Get accustomed to the gun, grip, trigger, and sights.
Shoot a few slow 5-shot groups at 25yd from a rest with your chosen carry ammo.
Shoot a few slow 5-shot groups at 25yd from a rest with the weakest practice ammo you can find, like WWB.
If there is a noticeable and repeatable difference between the targeting (windage & elevation) of the two types of ammo then you've got an issue. If not, you're good to go.
Well, after a practice session last month where the POA / POI difference was observed to be ~ 8" at 25 yds (hitting high) with 124gr Lawman, I called S&W, got the Warranty return label and sent the pistol off to the factory. It just returned with a test target and note stating that the pistol is within spec, no repairs completed. The test target shows a nice 5 shot 1" group at 15 yds at 1.25" above POA. (Win 115gr FMJ) Basic trig would say that at 25yds the group should be ~2.1" above POA. This is a DSV production run from last year, with 6390 rounds downrange.
My next step is to follow the advice Todd recommended with shooting for groups with the 124 Lawman and 124gr +p Gold Dots to see what is happening. Also time for a recoil spring change, I think...
Cheers,
Pk
mtdawg169
06-10-2011, 09:39 AM
Well, after a practice session last month where the POA / POI difference was observed to be ~ 8" at 25 yds (hitting high) with 124gr Lawman, I called S&W, got the Warranty return label and sent the pistol off to the factory. It just returned with a test target and note stating that the pistol is within spec, no repairs completed. The test target shows a nice 5 shot 1" group at 15 yds at 1.25" above POA. (Win 115gr FMJ) Basic trig would say that at 25yds the group should be ~2.1" above POA. This is a DSV production run from last year, with 6390 rounds downrange.
My next step is to follow the advice Todd recommended with shooting for groups with the 124 Lawman and 124gr +p Gold Dots to see what is happening. Also time for a recoil spring change, I think...
Cheers,
Pk
How long did Smith have your gun? I'm dropping a new 9FS off at fedex today. Mine was bought last month and has approx. 510 rounds through it. With Trijicon HD sights, its shooting 6-8" low at 25 and shoots low from 5 yds -25 yds using WWB. Group size is about the size of a paper plate at 25 yds from a sandbag. I'm using the same sights on a 9c and it doesn't have this problem.
IIRC: Mine took about a week to get back, unrepaired.
How long did Smith have your gun? I'm dropping a new 9FS off at fedex today. Mine was bought last month and has approx. 510 rounds through it. With Trijicon HD sights, its shooting 6-8" low at 25 and shoots low from 5 yds -25 yds using WWB. Group size is about the size of a paper plate at 25 yds from a sandbag. I'm using the same sights on a 9c and it doesn't have this problem.
1 week turn-around, gun test fired but not repaired. Didn't have a chance to get to the range this week but will look at 15yd and 25 yd accuracy with practice and carry loads before and after a recoil spring change. I'll report back what I find out.
Cheers,
Pk
1 week turn-around, gun test fired but not repaired. Didn't have a chance to get to the range this week but will look at 15yd and 25 yd accuracy with practice and carry loads before and after a recoil spring change. I'll report back what I find out.
Cheers,
Pk
Well…it isn’t the pistol.
While there is room for error and interpretation (and certainly the assessment could have been conducted with additional data), there are a few conclusions I feel comfortable making after spending some time yesterday evening evaluating whether or not there is a serious issue with this pistol (e.g. the early unlock).
Caveats: After a few long days at work without much sleep, my eyes were not 100% making it more difficult to maintain a consistent sight picture and group. The rest used at the NRA range in Fairfax was simply a place to rest the pistol frame, not to rigidly hold the pistol from shot to shot. I only used 5 shot groups to measure impact of changes. I only tried one brand of ammo (124gr Speer Lawman FMJ and 124gr +P Speer Gold Dots). I did not use any MOA calculation program – simply measured the distance (center to center) of the two farthest impacts and then eyeballed the center of mass of the 5 shot group to come up with the vertical and horizontal POI shift. Finally, I only ran one trial at each evaluation point.
Evaluation points: An observed trait of some full size M&P pistols is for the weapon to generate acceptable groups up close (~ 7 yds) close to POA, but with the same ammo, the groups have a significant POI shift when shooting at 25 yds. Several weeks ago, I (along with a few members of this forum) observed my M&P9 shooting ~ 8 inches high at 25 yds while POI shift from POA at the 5 yd line was insignificant. After sending my pistol back to the factory for an evaluation, the test target was returned showing a nice centered group at 15 yds using WWB 115gr FMJ ammunition. No repairs were made to the pistol and it was promptly returned to me. Concerned that a 15 yd test fire would not show the phenomena we observed at 25 yds, I went about my own series of test fires from a bench at NRA last night. I looked at my practice and carry ammo (124gr Speer Lawman FMJ and 124gr +P Speer Gold Dots) at 15 yds and 25 yds using the same point of aim and I conducted a second set of trials where I duplicated the strings after switching out the recoil spring (the original had 6300 rounds through it and it was time to switch it out) with a new one.
Results:
I’ve attached 3 of the test targets in case anyone wanted to look at the raw data. http://i133.photobucket.com/albums/q43/Pk14_photos/124grPw-6300rdsonRS.jpg
(124gr +P GD w/ 6300rds through Recoil Spring)
http://i133.photobucket.com/albums/q43/Pk14_photos/124grw-0rdsonRS.jpg
(124gr w/New recoil spring)
http://i133.photobucket.com/albums/q43/Pk14_photos/124grPw-20rdsonRS.jpg
(124gr +P GD w/New Recoil spring)
In a table form, here are the measurements –
15 yds 25 yds
Group Size 124gr FMJ New Recoil Spring 2.4” 4.0”
124gr +P GD Old Recoil Spring (6300 rds) 2.0” 4.75”
124gr +P GD New Recoil Spring (20 rds) 1.6” 4.5”
POI shift from POA 124gr FMJ New Recoil Spring O” deflection, 0.75” Up 1” Right, 1.3” Up
124gr +P GD Old Recoil Spring (6300 rds) .75” Right, .9” Up 2.1” Right, 0.5” down
124gr +P GD New Recoil Spring (20 rds) 1.6” Right, 0.5” Up 3.0” Right, 1.8” Up
Conclusions: I didn’t see a dramatic shift in POI moving from 15 yds to 25 yds with either my practice ammo or carry ammo. If I isolate the variables here are the three conclusions I’ve arrived at:
Changing the recoil spring (from end of service life to new spring):
o Group size is unchanged
o Windage is about the same for POI deflection from POA
o Change in elevation was 2.3” up moving from 15yds to 25 yds. Within acceptable tolerances? For the caveats noted above, my inclination is to say yes. A fresh eyes and another run would improve group size. The target POA could be adjusted to make it easier to consistently line up the sights against the target. But a 2.5” shift in elevation over the course of 6300 rounds is not going to be an abrupt change like shifting ammo types might be. I should still be able to hit an 8” plate if I’m holding COM with properly lined up sights.
Changing the ammo from P to +P (same bullet weight, same manufacturer):
o Group size impact inconclusive (pretty close)
o Definite shift to the right in POI from POA (might be worth a quick tap on the rear sight to help line things up better)
o ½” elevation change (about the same).
So there it is. I can’t explain why we saw an 8” POI shift a few weeks ago. This test helped me restore a little confidence in the pistol and that I just need to do a better job shooting it!
Cheers,
Pk
ToddG
06-16-2011, 08:42 AM
The difference between 115gr WWB and 124gr Lawman is pretty significant.
If you don't feel you're getting your best groups due to vision, etc., then you shouldn't draw too many conclusions about the test results. That's especially true when you use such a tiny aiming point.
The difference between 115gr WWB and 124gr Lawman is pretty significant.
If you don't feel you're getting your best groups due to vision, etc., then you shouldn't draw too many conclusions about the test results. That's especially true when you use such a tiny aiming point.
Very true! My original plan when I created the target was to use the small black dot with the Crimson Trace laser grip as the aiming method - they matched up pretty well out to 25 yds (dot size) and not centering the black dot on the sheet was to account for an expected larger POA / POI shift. Unfortunately, the CT grips were not aligned with the iron sights (I had removed them prior to sending the pistol up to S&W) and had not bothered to check the alignment between the laser and the iron sights before heading to the range. My first attempt at a group was half off the page to the right at 25 yds, and without the tiny allen wrench, I defaulted to irons.
I'll bring a box of WWB 115gr and a different target to see how that changes the results.
Cheers,
Pk
ToddG
06-16-2011, 11:55 AM
FWIW, I would use a standard NRA bullseye and aim for the bottom of the black bull. It's a very easy aiming reference at distance and less likely to fatigue your eyes. Of course, you then need to use that point (the 6 o'clock of the bull) as your expected POI.
I'd also shoot at least three groups with each type of ammo. When I do real accuracy testing, I always shoot at least five groups per ammo type. It's time consuming and tiring both mentally and visually. I've been known to occlude my non-dominant eye when accuracy testing... the only time I ever do so.
mtdawg169
06-17-2011, 09:54 AM
Got a call from S&W CS this morning stating that they were ready to send my M&P9 back to me. He couldn't tell me anything about what work was done to the gun. He only told me that the smith said my pistol was shooting low because the trijicon HD sights were too tall and offered to send a fiber front sight back with the gun. I call BS. I have the same sights on a 9c and it shoots poa/poi at 25 yards. The FS shoots 6-8" low. I explained this and all he could say was that is all the smith told him. I don't even know if they replaced the barrel to correct the poor groups I was getting. I will see how it shoots when it gets back, but I'm not overwhelmed with S&W's CS at the moment.
A visit to the factory later:
http://tapatalk.com/mu/a6cd092d-c884-9ae6.jpg
I'll shoot it either tomorrow or Monday and report back.
I also got a goofy 10 round mag back with my gun which is odd seeing as how I didn't send a magazine with the pistol.
At least something was done about the problem, even if it's not fixed.
"A" for effort.
ETA: New recoil spring assembly too.
Sorry for the delay in the updates. Been in Dallas watching baseball. :D
New barrel. Old barrel. Same shit.
No accuracy improvement from a barrel swap. I would post a picture but you'd be pressed to tell the difference from the others I've put up.
Slavex
07-01-2011, 01:19 AM
I thought heavier, slower bullets were more affected by barrels unlocking early? Perhaps I'm wrong (I usually am it seems) but wouldn't lighter faster bullets be leaving the barrel sooner than the slow ones, therefore sooner in the unlocking/recoil pulse process? This is what I've been told in regard to my CZ's, they are regulated to shoot with 124gr bullets and I use 147 so I need a taller front sight as the barrel is starting to unlock at a different time than it does with 124's.ulated to shoot with 124gr bullets and I use 147 so I need a taller front sight as the barrel is starting to unlock at a different time than it does with 124's.
ToddG
07-01-2011, 06:33 AM
A pistol barrel should stay locked more than long enough for just about any speed bullet to leave the muzzle. Slower bullets tend to have a slightly higher POI because the gun is recoiling. In human hands recoil means the gun -- and thus the muzzle -- tilts upward. The difference should be relatively slight.
When the barrel unlocks early in a tilt-barrel design, you get a far more pronounced change in elevation. The early unlocking is going to be more noticeable with lower pressure loads (regardless of bullet weight).
RockBottom
11-20-2011, 10:48 PM
I'm in the market for an M&P9, and just came across these posts about the unlocking issue. Todd G specifically, as well as the rest of you, I'd love to get your input about whether this problem would deter you from buying an M&P9. Also, does this problem occur with the M&P40? I read on the http://mp-pistol.com board that it only affected the full-size M&P9. Thanks much in advance for your replies!!!
Nephrology
11-21-2011, 11:33 AM
This seems to be the natural consequence of downchambering a gun designed for .40 to 9mm, much like glock had difficulties getting their .40s to work (especially with weaponmounted lights)
This seems to be the natural consequence of downchambering a gun designed for .40 to 9mm
I don't think that is here case here:
... The whole lockup problem began when Smith had to change the hood profile for the Compact barrels (the original design from the full size guns was too tight). For whatever reason, they decided to make the change universal for all 9mm barrels and so the Compacts lock up right and the longer barrels sometimes don't. ...
http://pistol-forum.com/showthread.php?924-M-amp-P-Bar-Sto-Barrel-from-Apex-Tactical-preview-pic&p=15061&viewfull=1#post15061
ToddG
11-21-2011, 11:58 AM
I've never seen an issue with the .40-cal M&Ps.
I've had one student whose M&P9 Compact shot very high at 25yd (more than 12") and even after factory service still shot unacceptably high (6-8" I can't recall off the top of my head). She dumped it for a Glock.
Someone mentioned in another thread that it only affects 1% of the guns. I'm not sure where that number comes from but if you ask the folks here at PF, you'll see a far greater percentage have experienced it. It might be more fair to say that only 1% of guns both (a) have the problem and (b) are shot accurately enough by their owners at distance to see the difference.
It would definitely be a consideration for me if I were in the market to buy a M&P9, but since S&W will work hard to fix it if they believe you've got a problem it wouldn't keep me from getting an M&P9 if that was the gun I otherwise wanted.
Nephrology
11-21-2011, 03:06 PM
I don't think that is here case here:
http://pistol-forum.com/showthread.php?924-M-amp-P-Bar-Sto-Barrel-from-Apex-Tactical-preview-pic&p=15061&viewfull=1#post15061
Very interesting. Thanks for the quote.
RockBottom
11-21-2011, 08:58 PM
I've never seen an issue with the .40-cal M&Ps.
It would definitely be a consideration for me if I were in the market to buy a M&P9, but since S&W will work hard to fix it if they believe you've got a problem it wouldn't keep me from getting an M&P9 if that was the gun I otherwise wanted.
Thanks! That's exactly what I wanted to know. In some ways it makes me reconsider going to the .40 instead, but the extra bullet cost really adds up over time so that's why I keep leaning towards the 9mm.
nbourbaki
11-21-2011, 10:48 PM
Can anyone comment on whether the Storm Lake Conversion barrel (.40->9mm) locks up properly with the .40 slide?
Thanks
Bob Hostetter
03-18-2012, 07:54 PM
If a handgun is unlocking early the will be a couple of different signs. One would be the group will string vertically. You would also likely see a tear drop shaped primer indentation from the firing pin not pulling back into the breechface prior to the barrel dropping. Since higher pressure would accelerate slide velocity and thus unlocking from the barrel why is it the opinion of the group that low pressure rounds would suffer from greater POI devation then higher pressure rounds. Both types of rounds should have exited the barrel long before the barrel unlocks. If the issue is vertical string then the first place I would look is at the fit of the muzzle end of the barrel to the slide and headspacing being too tight.
If a handgun is unlocking early the will be a couple of different signs. One would be the group will string vertically. You would also likely see a tear drop shaped primer indentation from the firing pin not pulling back into the breechface prior to the barrel dropping. Since higher pressure would accelerate slide velocity and thus unlocking from the barrel why is it the opinion of the group that low pressure rounds would suffer from greater POI devation then higher pressure rounds. Both types of rounds should have exited the barrel long before the barrel unlocks. If the issue is vertical string then the first place I would look is at the fit of the muzzle end of the barrel to the slide and headspacing being too tight.
My gen three Glock had the tear dropped shape on the primer. I always wondered why it did that.
They know there is an issue but won't do anything about it.Rem UMC shoots like crap in my 9mm with at least half the primers having firing pin tear drop markings.You can clearly see them.I sent my pistol in and they said it meets their standard with a certain brand of ammo.I can get the pistol to shoot good with light charges of unique and 147LFN bullets since they are so soft.I won't buy another S&W untill they get their act together.I've never seen so many flyers screwing up groups on a pistol as my M&P 9mm.Even with the FP drag marks on the primers they still try to say nothings wrong.
I got some win 147HP's loaded with Power Pistol that will have more pressure and see if a Plus P load works better and leaves drag marks on the FP.One thing good about the pistol is it never jams.Guess you just wait till they get within 10 yards and shoot super fast since it'll run no matter what.
see if a Plus P load works better and leaves drag marks on the FP.Even when my M&Ps weren't unlocking early and producing horrible groups, they had an elongated primer hit.
Even when my M&Ps weren't unlocking early and producing horrible groups, they had an elongated primer hit.
Maybe it's a M&P thing.I see a teardrop looking shallow extrusion going in the other direction of the FP drag.The drag is a lot longer than my stock colt 10mm shooting heavy loads.The primers look fine with it and only a very slight drag mark occasionally that can only be seen under a magnifying glass.Slide velocity on a 10mm can get pretty fast even at safe pressures because the FPS is fast.My 10mm shoots 1450fps with 155 grain bullets,still accurate and no FP drag,extrusion or any other weird stuff.I really like the M&P pistol in a lot of ways but it shoots pretty crappy with most ammo.It's a 10 yard pistol for SD to me so far and past that I wouldn't want to bet my life on it.A flyer at the wrong time could be fatal in a CB situation.
stevet1
05-11-2012, 09:22 AM
I used to be a pretty good shot with my M&P. After I got my Ruger 22 I started shooting that a lot because ammo is cheap so you you can shoot a lot, it's got very light recoil and it is really fun to shoot bull's eyes so effortlessly. When I went back to my 9 it was like I was starting to shoot all over again. You really notice the recoil and blast compared to a 22. My shots were randomly placed and I thought it was the gun. I tried another 9 and the same thing. Finally I asked a few god shooters to fire my gun at the range. They were hitting bullseyes with my gun and impressed at how accurate it is. It sounds really basic but have someone else shoot your gun just to make sure. I've been shooting my 9 more now and it's surprising how much better the gun has become.
http://pistol-forum.com/images/smilies/smile.png
I got my 9mm shooting pretty good after finding a few handloads that it likes.The BF makes the extrusion mark and the FP drag is no big deal I read on the M&P forum.I've been used to a tight 1911 that shoots 1 inch.I guess I shouldn't have thought the striker pistols should come close.1911's are so easy to completely disassemble and put back together I probably will always prefer them.Parts are easy to find and put in if something wears out or breaks.I do like the M&P a lot but the trigger and accuracy of a 1911 is second to none.I'd buy another M&P if they ever make a 10mm.
rsa-otc
05-18-2012, 02:43 PM
I recently had a conversaation with a S&W sponsered shooter whom I am friendly with about this very subject. He was adamate that the problem had nothing to do with early unlocking. It was his contention that it had to do with the rifling/chambering. That M&P 9's like light fast bullets, that if you are using heavy bullets like 147, you need them to be loaded as long (far out of the case) as possible. Just so they will chamber and fit in the the mag. He is a USPSA GM and IDPA DM. All his M&P's run stock barrels with exception of is open gun running 40 major. Julie G has also chimed in saying that she runs stock barrels on her M&P's as well. You can't fault their results. I have had the opertunity to shoot this person's guns and can tell you they are as he claims stock.
That's not to say there aren't accuracy problems with the M&P9 FS. It concerns me that it is more ammo sensitive than it's competitors. But maybe we are chasing the wrong reason for this sensitivity.
Pennzoil
05-18-2012, 05:26 PM
Regardless of what’s causing the 9mm accuracy issues the thing that sticks out to me is that S&W appears to be perfectly happy doing nothing to fix the issue. Mine are now safe weights waiting for S&W to get their head out of the sand which I'm doubting will ever happen.
He was adamate that the problem had nothing to do with early unlocking.I don't have the links handy, but one gunsmith was welding up the barrel lugs to increase the lock time which successfully solved the problem on his guns.
It's entirely possible there is more than one problem. Some guns unlock early causing accuracy problems, and others have accuracy issues because of the twist rate and chamber dimensions.
ToddG
05-18-2012, 05:37 PM
The problem with the twist rate theory is that all the guns have the same twist rate. Some are very accurate with all ammo, some are not. Inadequate stabilization also wouldn't explain why weak ammo prints so high compared to high pressure ammo, regardless of bullet weight.
Furthermore, all of the "Langdon" barrels were made with the same standard S&W twist rate, and they're all incredibly accurate with every type of ammo tested.
I don't have the links handy, but one gunsmith was welding up the barrel lugs to increase the lock time which successfully solved the problem on his guns.
Post 6 here (http://mp-pistol.com/boards/index.php?/topic/15034-match-barrel/)
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