S&W 4006 conversion to 9MM!

italiansport · #1 08-14-2018, 03:19 PM

I have searched this forum and looked elsewhere but have yet to come up with a direct answer to this question. Can a 4006 be converted over from 40S&W by merely changing to a 9MM barrel? If so what barrel would be used?
Jim

armorer951 · #2 08-14-2018, 08:55 PM

In a word, no. (and with so many great 9mm's out there, why?)

ken158 · #3 08-14-2018, 10:12 PM

No and why would you? You could make it a 357 Sig though...

italiansport · #4 08-15-2018, 12:49 AM

This is interesting since you can convert a Beretta 92(9mm) to a 96(40S&W) simply by changing barrels and mags and vice versa!
Jim

JohnHL · #5 08-15-2018, 02:02 AM

The 9mm barrel will not fit in the 40 frame without narrowing at the base.
(Then it will fit.)

The breech face on the 40 slide is larger and therefore the extractor is farther from the case rim.

The 40 barrel bushing is also larger than the 9mm.

Also the 40 recoil spring is heavier than the 9mm.

The 9mm mag will lock in the 40 magwell (but not vice-versa).

The conversion I've seen utilized a thinned 9mm barrel with 9mm slide and recoil spring with a 9mm mag.

The TSW models are a different story for a different time.

John

italiansport · #6 08-15-2018, 11:38 AM

I've got several 9mm's I just thought it would make for a more versatile pistol! Thanks for the information.
Jim

1sailor · #7 08-15-2018, 12:24 PM

You got that backwards on the Beretta's. You can convert a Beretta M96 to 9mm by swapping barrels but cannot go the other way without changing the slide due to the breech face size. The same can be done with the M&P40. I have fired thousands of rounds through both of those guns by doing the barrel swap.

Yorkie Man · #8 08-18-2018, 07:52 AM

I have converted several but what you will need is a 9mm slide because of the aforementioned details. One thing you will have to do is reduce the diameter of the lug on the bottom of the 9mm barrel to fit the .40 caliber slide. I have also rechambered a 9mm barrel to 357 Sig for both of my pistols but for that you will have to open up the breech face on the slide to accommodate the wider cartridge rim and use a heavier recoil spring.

I was amazed how accurate the 357 Sig cartridge is compared to the 9mm out of the same barrel after rechambering.

PM me if you have any questions.