A Cause of S&W M&P9 Inaccuracy

[Rich]

I don't pay much attention to close quarter groups. Until I get a pistol at 15+ yards and test it, I know absolutely nothing. And 15 yards is where I found my first M&P 9 was a turd. I was doing some of my structured B-8 bullseye work with the gun and started noticing that impacts were not matching up with my shot "call" on the shots. Bench testing at 25 yards showed that I was the proud owner of a pistol that was capable of 10 shot groups of 8-10" with anything I tried in it.

I had a pistol that beats it.

Gen 1 P85

[Slavex]

I thought we'd read somewhere that it was all the barrels fault? Didn't Ernest or someone have a barrel that S&W made up that fixed the issue?

[GJM]

When I was in my M&P accuracy throes struggle, I returned numerous 9FS pistols to the factory. Their "fix," which really didn't solve my issues, was to change the slide, barrel or both. Since the slides are not serialized, I couldn't always be sure what they did.

Those problem pistols all shot one or two loads acceptably, while being lousy with other loads. There was no pattern as to which pistol shot which load well.

[JV_]

It's a bit of an assumption to think the issues that caused their accuracy problems 5+ years ago are the same ones causing it today.

They've had a number of barrel iterations, changed the finish process, modified numerous internal parts, etc.

Sometimes, it is like playing whack-a-mole.

[LOKNLOD]

I think the "pleasant to shoot" factor is much higher on the m&P .40s than the 9mm, relative to competitive pistols. If the "material removal for pleasantness" was correct , wouldn't it impact the .40 even more so than the 9?

And does slide material removal automatically translate to pleasantness?

[BLR]

It's a bit of an assumption to think the issues that caused their accuracy problems 5+ years ago are the same ones causing it today.

They've had a number of barrel iterations, changed the finish process, modified numerous internal parts, etc.

Sometimes, it is like playing whack-a-mole.

I strongly disagree.

There are still fleas there. For example, all those pretty, but complex shapes milled into the slide? If you heat treat, melonite, whatever AFTER machining, those are all wonderful places to induce warpage. Thicker/higher mass just masks it to a larger extent.

Then throw in FNC was never meant for alloy steel, like stainless, and you have a whole field of land mines to contend with.

This is what happens when the biddness and markety types do design work.

(And there was a reason I only put up a partial solution online, )

[GJM]

Bill, I have lost track of the technical analysis. It would be very helpful if you summarize, in the cliff notes version, what the problem or problems are, and what it would take for S&W or someone else to fix the problems causing the accuracy issues? Also, why these problems don't seem to effect the .40, .45 and Shield pistols. Thanks in advance.

[Urban_Redneck]

I strongly disagree.

There are still fleas there. For example, all those pretty, but complex shapes milled into the slide? If you heat treat, melonite, whatever AFTER machining, those are all wonderful places to induce warpage. Thicker/higher mass just masks it to a larger extent.

Then throw in FNC was never meant for alloy steel, like stainless, and you have a whole field of land mines to contend with.

This is what happens when the biddness and markety types do design work.

(And there was a reason I only put up a partial solution online, )

FNC- Ferritic Nitro Carburizing ?

[JV_]

I strongly disagree.

So you've looked at a recently manufactured M&P to confirm they have the same issues that they had years ago, and the root cause is still the same?

[orionz06]

So you've looked at a recently manufactured M&P to confirm they have the same issues that they had years ago, and the root cause is still the same?

Maybe Doc can hook him up with one of his new M&P's that are fixed?