Help with new M&P40 FS - POI for .40 & 9mm

[CTDE_TA]

Hoping to get some expert opinions on this... I've got a brand new M&P40 Full Size (1.0) that I took to the range for the first time today. I was very happy with function and accuracy over about 150 rounds. I'd read that many owners have also purchased a factory 9mm barrel and mags, so I did the same and also tested that out today. I'm happy to say that it functioned perfectly; no problems at all. However, I found that point of impact for 9mm rounds (Magtech, MEN, Lawman) was consistently low - probably at least 2" at 10 yards.

Has anyone that's tried this (or similar) setup had this same issue? I do understand that there is some controversy about using the factory 9mm barrel in the M&P40. It functioned flawlessly, but is it possible it could cause this low POI due to a less perfect fit of the factory 9mm barrel in the .40 slide?

A friend I was shooting with had a Glock 23, and he was using a factory .40 barrel and a 9mm KKM conversion barrel, and my POI when shooting his pistol was consistent between the two. Do you think I'd have a more dependable POI with the M&P if I ponied up and bought a KKM conversion barrel?

Really appreciate any feedback on this experience. Thanks!

 

[OKFC05]

That's why nobody will guarantee perfect results with a drop-in barrel, different caliber or same. Each piece has manufacturing tolerances, and if the tolerances stack in the wrong direction, there will be variation in POI. Generally, the barrels shoot to about the same POI and function reliably, but no guarantee.
There is also no guarantee that a drop-in KKM will shoot to the same POI; it may be the slide that's a touch off, or your original barrel may be pushing tolerances.

 

[CTDE_TA]

Thanks, appreciate the reply.

 

[LoneStarWings]

Yes, it is very possible due to the tolerance dimensions of the slide and barrels unfortunately. My KKM 40-9 conversion barrel for my compact shifted the POI about 4" right at 25 yards. Luckily it was easily correctable by drifting the rear sight left about 1/20th of an inch. The conversion barrels for my 5" M&P 40's didn't really have a change in POI.

 

[hyena]

This is not the caliber change you asked about, but I offer it just as an FYI. I have an M&P FS in .357SIG, and recently bought a 9mm S&W barrel from Midway for $73, along with an S&W 9mm magazine.

Point of impact and accuracy did not change at all. I'm very pleased, since 9mm is so much cheaper to shoot.

 

[MrOldtimer]

Best to get the conversion barrel. I have a Storm Lake 40 to 9mm conversion and notice no difference in point of impact. The 9 does save me some money on ammo costs.

 

[mnarcher]

I am curious about this also.

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