M&P 9mm accuracy issues?
- Thread starter rcamp
- Start date
When you say ordered do you mean paid $$$ for? Or is it a customer service replacement?
At the present time I'm not terribly impressed w/S&W's 9mm barrels. If I was paying, I'd be buying a KKM again...and I'd call them back and cancel the order.
1sailor
Member
I'd wait for the barrel to arrive and try it out. As I've gotten more experience with my own the group sizes have tightened considerably. At 25 yards from a sitting position I can pretty consistantly keep my groups below 3" with 10 rds in the mag. If you're not happy you can resell it for a big portion of what you paid for it. Comparing my experiences to others it seems to be a hit or miss kind of thing. I have the old style barrel by the way.
Martimus
US Veteran
I broke down a while back and ordered a barrel for my M&P9 from Brownells. The accuracy of my M&P9 improved significantly after installing that barrel.
I swapped back and forth between barrels to insure that my experience wasn't a fluke. As such I think it prudent to say that either I had a real lemon of a barrel or the new S&W barrels are an improvement over the older ones.
In Canada, there are only a few companies that Import Barrel's and other Firearm related items. So they ordered the Barrel for me and i'll pay before they ship it to me.
I've been doing a lot of reading of various posts on this issue and it seems the accuracy of any particular M&P 9mm is luck of the draw. Some have decent accuracy, while others cant keep it on the paper at 10yds.
From what I've read, I'm starting to believe that how tightly the locking block (aka barrel hood) fits into the slide notch determines the accuracy potential of that particular barrel/slide combination. If that is typically smaller than a .40 version, I can see that affecting using 9mm barrel in a .40 slide but I don't know why that would be a factor with a stock 9mm as it should be machined to fit correctly.
The other lockup issue I hear talked about is that the 9mm unlocks too soon and the bullet is then thrown high by the barrel pivoting down. I think this might be what bharner is talking about above and what others say a fix is being worked on by a popular aftermarket vendor.
So with the cost of buying a new gun, a trigger improvement, a couple other parts and a barrel, with no guarantee it will still shoot accurately, it isn't unreasonable to just go buy another brand and not have to monkey with it.
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Oh no.....
I had just about decided to buy an XDm instead of taking my chances with a Pro that may or might not need a lot of aftermarket mods to shoot to my expectations.
My wife went with me to the weekend IDPA match and got to talking with one of the gals and now she wants a M&P 9 because if fits her hand so well!.... now what do I do if it turns out to be a crappy shooter?
Is there a way to maybe measure the barrel hood to slide fit with feeler gauges or some other in-store measurement spec-check to hopefully get a good one?
I had just about decided to buy an XDm instead of taking my chances with a Pro that may or might not need a lot of aftermarket mods to shoot to my expectations.
My wife went with me to the weekend IDPA match and got to talking with one of the gals and now she wants a M&P 9 because if fits her hand so well!.... now what do I do if it turns out to be a crappy shooter?
Is there a way to maybe measure the barrel hood to slide fit with feeler gauges or some other in-store measurement spec-check to hopefully get a good one?
I got a factory drop in 9mm barrel for my M&PC 357sig about a month ago.
I am very happy with it, it is very accurate.
I guess S&W is shut down until Aug 13th, so i should receive the barrel near the end of the month. I'll give a range report after i get it.
The link below is to some targets shot with my M&P Pro
with the factory barrel & after market barrel
This was done standing @ about 15 yards -- rapid fire.
We shoot action pistol defence - shoot double tap , move -- shoot while moving
theory being if you stop your history.
wished to go into depth but this was a one time for each type bullet due to a strong hand injury .
after I get my surgery will redo the test when I heal and the after market barrel gets broke in . & with 124 gr. bullets also.
Pictures by balloons61 - Photobucket
FYI
I'm new to this forum. I read everything in this post but am not a gunsmith so I don't understand everything.
I bought a S&W M&P 9mm full size about 6 weeks ago. I ran a box of American Eagle 115 gr through it at 10 and 15 yards. It shot 5" low and 5" left for myself. I let my friend shoot it. He shot the same.
I called S&W and they said to send it back. I got it back on 8/1/12. S&W put a lower front sight on the gun. I ran a second box of the same ammo through it. It sprayed all over the 8" target at 15 yards. I shot it a 10 yards and was able to put 5 shots in a 2" group after adjusting the rear sight.I could not understand why it sprayed all over the target at 15 yards. Each time I was shooting supported.
I changed Ammo to Winchester 115 gr solid points. Again, I shot it supported and could not hold a group at 15 yards.
Correct me if I'm wrong but a lot of guys are having the same problem. Can't the S&W M&P 9mm hold a group at 15 yards?
What should I do?
I previously had a S&W Model 15 38spl revolver and could hold a 2" group at 25 yards.
I bought a S&W M&P 9mm full size about 6 weeks ago. I ran a box of American Eagle 115 gr through it at 10 and 15 yards. It shot 5" low and 5" left for myself. I let my friend shoot it. He shot the same.
I called S&W and they said to send it back. I got it back on 8/1/12. S&W put a lower front sight on the gun. I ran a second box of the same ammo through it. It sprayed all over the 8" target at 15 yards. I shot it a 10 yards and was able to put 5 shots in a 2" group after adjusting the rear sight.I could not understand why it sprayed all over the target at 15 yards. Each time I was shooting supported.
I changed Ammo to Winchester 115 gr solid points. Again, I shot it supported and could not hold a group at 15 yards.
Correct me if I'm wrong but a lot of guys are having the same problem. Can't the S&W M&P 9mm hold a group at 15 yards?
What should I do?
I previously had a S&W Model 15 38spl revolver and could hold a 2" group at 25 yards.
If you mention what you didn't understand someone might be able to explain it to you. There aren't any stupid questions here, except the ones I ask.
I've searched around the various forums for answers to this accuracy question and haven't yet come across a thread that explains it. If anyone knows, they aren't spreading the news with details. Another issue you will hear quoted often is something about lockup timing - again without specifics.
So I have come up with my own theory but of course cant prove it due to lack of data and a lot of the supporting comments are hearsay. It goes like this...
Lockup refers to when the barrel and slide are fully forward and ready to fire. The parts involved are the recoil spring for tension and the barrel hood extension that fits in a recess at the slide breech face. The barrel and slide should be held in place together fairly tightly.
How well the barrel and slide fit together, in the same repeatable alignment shot after shot, will have a lot in determining that guns accuracy or lack of it. For whatever reason (by design, manufacturing tolerances, different subcontractors etc) the barrel and slide can have slop from an accumulation of tolerances.
I think that the more play, slop, gap there is between the barrel and slide at the lockup recess, the less accurate the gun will shoot because the barrel will be pointing slightly different than the sights each shot. Some people have reported using a stiffer recoil spring has helped a little. YMMV
If you slowly pull your slide back you'll see the rear of the barrel slides downward and the muzzle tips upward. This is the process of unlocking. At some point the slide will continue rearward extracting the shell case, stripping another off the magazine and feeding it into the chamber and the barrel will slide back up into locked position, all thanks to the recoil spring.
Under the barrel, (below the chamber block) is a slot that fits in a bar in the frame, that cams the rear of the barrel down as the slide travels rearward. The shape of this slot determines the lock/unlock timing of the barrel cam action. You would probably have to have an animated 3-D engineering model and to understand and/or modify anything to do with this area. I think this is what people are referring to when they say the 9mm M&P can unlock early. If the barrel unlocks early, the barrel starts to tip upward before the bullet has exited the barrel, thus POI high on the target. This typical would happen with heavier bullets like 124 & 147gr. If shooting 115 or fast 90's brings the POI down then early unlocking might be the problem. Fixing this would take complete re-engineering of the system.
In a previous post I mentioned I had measured several barrel dimensions between a OEM 9mm and OEM .40 barrel and the only difference I could find was the width of the barrel hood.
My 9mm measures .397" and the 40 is .427" - a difference of .030."
The corresponding recess in my slide is .430", the .40 barrel has only .003" clearance and locks up tight. So, the 9mm has .033" of slop to move around in which gives me 2.5" groups at 10 yds out of my compact - not a tack driver but acceptable for social work.
I also tried approaching this from another angle. With each barrel assembled in the gun and the slide closed, I used a blade feeler gauge to measure the gaps where ever I could get in around the hood/slide fit and also between the chamber block and the left inner side of the slide.
The gap between the front of the chamber and slide was the same with both barrels (.006") and the gap at the rear of the barrel (at loaded indicator hole) was also about the same. There wasn't any front to back play. I couldn't get my gauge into the L/R sides of the hood, so instead I used my fingers to push the chamber block left and right to get the maximum lockup gap I could in both directions and measured the change in gap between the left inner-slide and the chamber block.
On the .40 it was .008" and with the 9mm barrel installed it was .017"
This was an initial quick look at ways to explain accuracy issues that seem to occur with some 9mm's and I did use a 9mm factory barrel in a 40 slide so it wasn't a matched set. You might also note that my second set of numbers don't match with my first set and you would be right. That doesn't mean were not on the right track.
Since the accuracy seems to be random and luck of the draw, I'm trying to come up with a reasonable method to check the gun with a feeler gauge in the store before you purchase it, to increase the odds of getting a good one.
All of this is just my guess of what might be going on. Measure your own barrels and see what you come up with. Sorry for the long post... already I had my nap today.
I've searched around the various forums for answers to this accuracy question and haven't yet come across a thread that explains it. If anyone knows, they aren't spreading the news with details. Another issue you will hear quoted often is something about lockup timing - again without specifics.
So I have come up with my own theory but of course cant prove it due to lack of data and a lot of the supporting comments are hearsay. It goes like this...
Lockup refers to when the barrel and slide are fully forward and ready to fire. The parts involved are the recoil spring for tension and the barrel hood extension that fits in a recess at the slide breech face. The barrel and slide should be held in place together fairly tightly.
How well the barrel and slide fit together, in the same repeatable alignment shot after shot, will have a lot in determining that guns accuracy or lack of it. For whatever reason (by design, manufacturing tolerances, different subcontractors etc) the barrel and slide can have slop from an accumulation of tolerances.
I think that the more play, slop, gap there is between the barrel and slide at the lockup recess, the less accurate the gun will shoot because the barrel will be pointing slightly different than the sights each shot. Some people have reported using a stiffer recoil spring has helped a little. YMMV
If you slowly pull your slide back you'll see the rear of the barrel slides downward and the muzzle tips upward. This is the process of unlocking. At some point the slide will continue rearward extracting the shell case, stripping another off the magazine and feeding it into the chamber and the barrel will slide back up into locked position, all thanks to the recoil spring.
Under the barrel, (below the chamber block) is a slot that fits in a bar in the frame, that cams the rear of the barrel down as the slide travels rearward. The shape of this slot determines the lock/unlock timing of the barrel cam action. You would probably have to have an animated 3-D engineering model and to understand and/or modify anything to do with this area. I think this is what people are referring to when they say the 9mm M&P can unlock early. If the barrel unlocks early, the barrel starts to tip upward before the bullet has exited the barrel, thus POI high on the target. This typical would happen with heavier bullets like 124 & 147gr. If shooting 115 or fast 90's brings the POI down then early unlocking might be the problem. Fixing this would take complete re-engineering of the system.
In a previous post I mentioned I had measured several barrel dimensions between a OEM 9mm and OEM .40 barrel and the only difference I could find was the width of the barrel hood.
My 9mm measures .397" and the 40 is .427" - a difference of .030."
The corresponding recess in my slide is .430", the .40 barrel has only .003" clearance and locks up tight. So, the 9mm has .033" of slop to move around in which gives me 2.5" groups at 10 yds out of my compact - not a tack driver but acceptable for social work.
I also tried approaching this from another angle. With each barrel assembled in the gun and the slide closed, I used a blade feeler gauge to measure the gaps where ever I could get in around the hood/slide fit and also between the chamber block and the left inner side of the slide.
The gap between the front of the chamber and slide was the same with both barrels (.006") and the gap at the rear of the barrel (at loaded indicator hole) was also about the same. There wasn't any front to back play. I couldn't get my gauge into the L/R sides of the hood, so instead I used my fingers to push the chamber block left and right to get the maximum lockup gap I could in both directions and measured the change in gap between the left inner-slide and the chamber block.
On the .40 it was .008" and with the 9mm barrel installed it was .017"
This was an initial quick look at ways to explain accuracy issues that seem to occur with some 9mm's and I did use a 9mm factory barrel in a 40 slide so it wasn't a matched set. You might also note that my second set of numbers don't match with my first set and you would be right. That doesn't mean were not on the right track.
Since the accuracy seems to be random and luck of the draw, I'm trying to come up with a reasonable method to check the gun with a feeler gauge in the store before you purchase it, to increase the odds of getting a good one.
All of this is just my guess of what might be going on. Measure your own barrels and see what you come up with. Sorry for the long post... already I had my nap today.
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Thanks for the reply. I guess that I don't know what I'm going to do with this gun. I probably should call the factory again. I can't see buying a new gun and having to put an aftermarket barrel, new sights, recoil spring, and a trigger job on it just to get the accuracy of what it should be doing right out of the box. Do you agree?
I agree 100%
Masterorion9
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Wow, I'm so glad I have one that keeps good groups. Although it could be better at distance, I think it's mostly me. Even after installing an Apex Tactical FSS & Trigger kit I still get the occasional flyer. Now, my groups have really tightened up after the kit install but damnit if those flyers don't urk me when they show up! I wish I could afford to test it more, or practice more so at this point I'm going to chalk it up to my own fault. Come to think of it, I used to practice w/ a Ruger MkIII Target model and I could make a pretty good ragged hole at 7 yrds. Can't keep it that tight on my M&P9 FS...
danysw
Member
As I said in another thread. My M&P9 Full shoots very well, way better than me. At 15 yards I'm shooting 2" groups which is better to what I get with my SR9c and equal to my Glock 19.
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Guys, the issue here is that some recent production 9s shoot well, others shoot less well/really bad.
Now, some of this could be explained as tolerance stack. For every dimension, there is a nominal dimension and a tolerance +/- of allowable variance. If you get a slide with breech area tolerances on the maximum limit and a barrel on the mimimum limit, accuracy is going to suffer.
Another possibility is that there could be one machine doing barrels that are out of tolerance or (if S&W isn't rifling their own barrel blanks) a supplier that is 'having issues'. The gent that reports a barrel throwing rounds 5" out to one side suggests that particular barrel has a bore that doesn't travel down the center of the barrel. This is something that very occasionally happens (although I'd really like to know how!) in a wide variety of handgun brands. Years later I recall a Colt 38 Super barrel whose chamber was 0.040 off center to the left.
The unlocking early claim was discussed in another thread. Any movement of the barrel breech is not unlocking. Only downward movement in a vertical plane is an unlocking action and that requires about 3/16" movement of the slide. Or at least it did in B-F serial series pistols.
Looking at that article on the 10-8 site, the original rifling spec has produced excellent accuracy in other model S&W pistols, that indicates that rifling twist has minimal significance in difference. However, it would appear that S&W bean counters decided to use one machine program to do all barrel profiles after development of the compact, regardless of end use. That would seem to be an error. The chamber area profiles of the original design are very similar to those used in the 1911, the P35 Browning and other pistols like the earlier S&W designs. These didn't have significant accuracy issues (or any issues-the nattering about stress risers to the contrary). It would seem that the easiest answer would be to return to the orginial barrel profile for full length and plus length pistols. There is another possible mechanical issue though: is there also a difference in locking blocks? Kinda doubtful, but slightly possible.
BTW, I can't speak for S&W, but one of the things we (plant maintenance) did during shutdown when I worked in a factory was a whole lot of machine tool rebuilding and replacement. Machines identified by QC as producing out of spec parts were taken off line when discovered and brought back into spec before being placed back into production. It would also be a good time to implement a decision to resume production of the old/another barrel profile for other than compact if they feel there is a market driven need that would justify the cost.
Now, some of this could be explained as tolerance stack. For every dimension, there is a nominal dimension and a tolerance +/- of allowable variance. If you get a slide with breech area tolerances on the maximum limit and a barrel on the mimimum limit, accuracy is going to suffer.
Another possibility is that there could be one machine doing barrels that are out of tolerance or (if S&W isn't rifling their own barrel blanks) a supplier that is 'having issues'. The gent that reports a barrel throwing rounds 5" out to one side suggests that particular barrel has a bore that doesn't travel down the center of the barrel. This is something that very occasionally happens (although I'd really like to know how!) in a wide variety of handgun brands. Years later I recall a Colt 38 Super barrel whose chamber was 0.040 off center to the left.
The unlocking early claim was discussed in another thread. Any movement of the barrel breech is not unlocking. Only downward movement in a vertical plane is an unlocking action and that requires about 3/16" movement of the slide. Or at least it did in B-F serial series pistols.
Looking at that article on the 10-8 site, the original rifling spec has produced excellent accuracy in other model S&W pistols, that indicates that rifling twist has minimal significance in difference. However, it would appear that S&W bean counters decided to use one machine program to do all barrel profiles after development of the compact, regardless of end use. That would seem to be an error. The chamber area profiles of the original design are very similar to those used in the 1911, the P35 Browning and other pistols like the earlier S&W designs. These didn't have significant accuracy issues (or any issues-the nattering about stress risers to the contrary). It would seem that the easiest answer would be to return to the orginial barrel profile for full length and plus length pistols. There is another possible mechanical issue though: is there also a difference in locking blocks? Kinda doubtful, but slightly possible.
BTW, I can't speak for S&W, but one of the things we (plant maintenance) did during shutdown when I worked in a factory was a whole lot of machine tool rebuilding and replacement. Machines identified by QC as producing out of spec parts were taken off line when discovered and brought back into spec before being placed back into production. It would also be a good time to implement a decision to resume production of the old/another barrel profile for other than compact if they feel there is a market driven need that would justify the cost.
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budrichard
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I have read this Thread with interest as my wife recently purchased a S&W M&P 9mm.
My background is in Engineering and QC/QA.
First, without the use of a machine rest such as a Ransom, all accuracy testing is really inconclusive and subject to the ability of the shooter and perceptions of the shooter.
Second, all the speculation of the cause of any inaccuracy is meaningless BS without a knowledge of how S&W designs, manufactures and assures thier products, IF thier is a problem to begin with.
I have seen this sort of problem identification and speculation get out of control before on the Internet and result in an 'Urban Legend' that seamingly never dies but get repeated 'ad naseum'.
I have still not seen objective information presented that there is a problem and certainly not any information about causation.-Dick
My background is in Engineering and QC/QA.
First, without the use of a machine rest such as a Ransom, all accuracy testing is really inconclusive and subject to the ability of the shooter and perceptions of the shooter.
Second, all the speculation of the cause of any inaccuracy is meaningless BS without a knowledge of how S&W designs, manufactures and assures thier products, IF thier is a problem to begin with.
I have seen this sort of problem identification and speculation get out of control before on the Internet and result in an 'Urban Legend' that seamingly never dies but get repeated 'ad naseum'.
I have still not seen objective information presented that there is a problem and certainly not any information about causation.-Dick
