M&P9 barrel saga

[JHC]

... said the guy on the F.A.S.T. Wall of Fame ...

Very solid data and not something that is likely to surprise most folks.

Out of curiosity, were the HKs LEM models or DA/SA?

LOL I seeee. Great shooting azant.

[LtDave]

I have 3 M&P pistols. A FS .45, a FS .40 and a 9L. I also have a .357 Sig and 9mm threaded barrel for the .40.

The 9L is the most accurate 9mm pistol I own. More accurate than my P210 and several HK P7’s. The .45 shoots great, but the .40 gun is just meh.

My accuracy standard is 2" at 20 yards from a rest. So far, the only way I can get 2" or better is with the .357 barrel in the .40. And I have tested a lot of different bullet weights, powders, etc. I have only found a couple of .357 loads that work to my satisfaction. Even more challenging is getting one that will shoot to the sights.

[TigerStripe]

Yeah, that was done off the books as I could not get them to do it as a program. The guy that helped me with this has been there at S&W for many years and has forgotten more about how guns work than I will ever know. He and the others helped me out and went out and had this done by the guys that build the barrels on the production line (as they have also be there for many, many years. Think 1970's time frame). I think we made like 7 barrels or something like that. They were all stainless barrels with no black finish like the production barrels. And they shot great.

Let me just say it did not go over well for me or the ones that helped me do this back then. No one got in any real trouble at the time as it never really full public at the time. But the word got out and there where ones that were not happy with what we did or how we did it. Because it worked, they could only make so much of a stink about it at the time. Almost all the barrels went to guys that where winning matches with the M&P, so that helped as well.

They could have paid you for (your input on) the barrel fix and had a pistol that was where the Glock was prior to the MIM extractor & Gen4 problems hit.

[mnealtx]

DocGKR, is it possible the "dots' you're seeing and were in that 10-8 posted picture are in fact Rockwell hardness test hits? And as such might have nothing to do with the twist and hood changes?

If that were the case, wouldn't they have been present on *all* barrels and not just the new ones?

[JV_]

If that were the case, wouldn't they have been present on *all* barrels and not just the new ones?

I don't think it's a safe assumption to say that QC tests never change. They may not have been doing hardness tests since the M&P's inception, but after discovering some issue, they've added it.

[mnealtx]

Yeah, that was done off the books as I could not get them to do it as a program. The guy that helped me with this has been there at S&W for many years and has forgotten more about how guns work than I will ever know. He and the others helped me out and went out and had this done by the guys that build the barrels on the production line (as they have also be there for many, many years. Think 1970's time frame). I think we made like 7 barrels or something like that. They were all stainless barrels with no black finish like the production barrels. And they shot great.

Let me just say it did not go over well for me or the ones that helped me do this back then. No one got in any real trouble at the time as it never really full public at the time. But the word got out and there where ones that were not happy with what we did or how we did it. Because it worked, they could only make so much of a stink about it at the time. Almost all the barrels went to guys that where winning matches with the M&P, so that helped as well.

Can you speak (in general terms) as to what type of changes were made to change the dwell time?

[mnealtx]

I don't think it's a safe assumption to say that QC tests never change. They may not have been doing hardness tests since the M&P's inception, but after discovering some issue, they've added it.

Agreed.

So, to prove the reverse... does anyone recall seeing 'dimple' barrels *before* the recent barrel change?

[tomr]

Ah, not necessarily it depends on the QC protocol, in this case, that S&W adopted. Inspection is expensive, modern technology facilitates a lot of it and lowers the cost, but sampling is quite normal in large production facilities. In fact this might explain why there's one and 2 dots out there. Sometimes a Rockwell test comes back with hardness either too soft or too hard, in which case a retest might be performed or a re-heatreat followed by a retest. In this case I'm asking what those dots look like (in the flesh) as its hard to tell from the pics whether they're in fact a mfg. change code or RC test hits. Dont know.

If that were the case, wouldn't they have been present on *all* barrels and not just the new ones?

[BLR]

The dimples I've seen aren't C scale perpetrator marks.

They could be B scale. If it is hardness, it looks like a 1/16 penetrator iirc.

Sent from my SGH-T889 using Tapatalk 2

[Molon]

Smith & Wesson M&P9 Pro Series C.O.R.E.




I recently purchase a new Smith & Wesson M&P9 Pro Series CORE pistol with a 4.25” barrel. This pistol has a serial-number prefix of “HBL” and the factory test-fire date is 5/17/2013. This pistol came from the factory with one of the “single-dimple” barrels previously described in this thread. I conducted a brief accuracy evaluation of this pistol at a distance of 25 yards shooting off of a bench with sandbags. Shooting was conducted with the pistol in its stock configuration, except for the mounting of a Trijicon RMR07 sight. (I did install an APEX trigger after the testing was completed, as you can see in the picture above.)

Control Ammunition. The ammunition used in this evaluation consisted of hand-loaded Hornady 124 grain FMJ-FP bullets (#35567B) with a nominal muzzle velocity of 1050 FPS. When fired from my 9mm test platform (a bench-rested Colt 6450 with a free-floated, stainless steel Noveske barrel with traditional rifling) this load consistently produces 10-shot groups at 25 yards that have extreme spreads of less than one inch. As an example, the 10-shot group pictured below has an extreme spread of 0.76”.





Control Group. Prior to shooting the M&P9, I fired a 10-shot control group at 25 yards using another polymer-framed 9x19mm pistol that has previously proven to produce acceptable accuracy; a Springfield XD(M) with a 4.5” barrel. This pistol was also fired in its stock configuration, with the exception of mounting a Trijicon RMR07 sight. The 10-shot control group (pictured below) had an extreme spread of 1.92” and a score of 100-9X on the B-8 target.






The M&P9. I obtained a rough-zero for the M&P9 pistol at a distance of 7 yards. A 10-shot group fired at that distance formed one ragged hole. Moving the target stand back to the 25 yard line, the M&P9 turned in a 10-shot group that had an extreme spread of 2.31” (shown below).





After a couple of adjustments to the RMR07 sight, the M&P9 was shooting dead-on for a POA=POI zero at 25 yards. A 10-shot group fired on an NRA B-8 target produced a score of 100-7X. The extreme spread for this group was 2.33”.










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