Will this barrel work in my Full Size M&P40? It's in stock and I would like to buy it if it will work.  It isn't the conversion barrel, I guess just the replacement 9mm barrel.
Storm Lake 9mm Threaded Barrel

Thank you, I guess I'll give it a whirl!

So I've finally saved enough to order me a shiny new full size M&P
Before I do I have a few ???

?1 = does the 9mm barrel work in the current generation 40

?2= does it work  with or without the thumb safety?

I would use the 9mm barrel in the 40  80% of the time.

?3 = for those of you who have done this conversion awhile ago do u  still find its a reliable combination

Wow no responses?
Come on guys ......

Thanks for the response

does this work with the 40 long?

So, just a week or two ago I ordered (back ordered) a 9mm barrel from Brownells for $78.xx. I was looking through the site today and the price has risen to $120.
Will they honor the back order price (providing they ever get them back in stock)?

Mine is more accurate with the 9mm barrel than the .40 barrel it came with. I also got the .357Sig barrel. It groups well, but seems to shoot a couple of inches left while the other two are well centered.

Did you ever get the barrel from Brownels?  I talked to S&W recently, and they stated they are no longer selling barrels to individuals, nor are they filling orders/backorders to shops/online stores/etc - new procedure is that customer must send gun back to S&W for a caliber conversion.

I have a M&P 40 i bought last December. Not sure the exact production date.   I tried using a S&W factory threaded 9mm barrel in it. It cycles a little clunky, but too clunky with actual ammunition for a solid lock up.  I literally could fire one round aad then the next would not lockup all the way.  I just bought a 9mm slide to try it with.

With a suppressor on it WILL NOT close all the way at all.

I shot an IDPA match this weekend with a 5" 9mm barrel in my 5"40. no functionality issues at all. I want to do more accuracy testing I had good hit in the match.

**i didn't read the whole thread**
Storm lake (or other) threaded 9mm in a .40sw gun? Still good to go ?
I see an assumed answer above...

I'm running the Storm Lake 9mm conversion barrel in my stock 40c with no problems of any kind. Couple hundred rounds through it with no issues.

Same here.

I can't really quote on the S&W magazines, however years ago I discovered that 9mm and .40 would interchange in Beretta 92 and 96 mags without any issues. That said, I'd at least try loading and function checking the .40 mags with 9mm before spending the extra money (unless of course you want it that way)

Can anybody confirm if this works for the shield?

I know this post is getting old, but it may be too good to die. There is a lot of experience here with the conversion of the .40 M&P guns to shoot 9mm with a barrel swap. My questions are,

bump

 
I'm in the same boat and wanting to know the same thing before I pull the trigger. Also, I've seen slides cheap enough on ebay to nab and am wondering if between the stock 9mm slide and stock 9mm barrel if it would be worth it just to buy both and never lose an ounce of sleep over it.

I've got both 40 and 9mm guns and have tried a drop in 9mm conversion barrel as well as interchanging the older style contour barrels with the newer production style.  Long story short, the only difference in the M&P 40 and 9mm full size is the slide mass and the breech face/barrel hood width.  The extractor, ejector and recoil springs are the same.  The ejector is different between the key lock and thumb safety style frames, but the same between calibers for each style frame.

If you run either a 9mm factory barrel or a conversion barrel in a 40 slide, reliability may suffer with 115 grain loads due to increased slide mass, not necessarily the barrel.  The weaker 9mm round has a more difficult time moving the heavier 40 slide.  The 9mm factory barrel hood will be more narrow than the 40 and might wiggle side-to-side more, but the barrel diameter, hood length and locking block design will provide adequate lockup for recreational shooting with no safety concerns.  A conversion barrel only tightens the barrel to slide fit very slightly during lockup by adding a wider barrel hood.  The drop in conversion barrel does not intentionally change any other dimension of lockup.  The only other difference in the factory 9mm and 40 barrels is the length of the feed ramps.  This difference is only to accommodate the different diameter rounds and does not affect mechanical function with other parts.  I have a factory 357 barrel too and I believe it may have yet another difference in the feed ramp.

Of course, if you can get the 9mm slide, no parts in the frame require changing.  That is the way to go for the best chance of reliability due to proper slide mass and a proper width breech to secure and guide the case of the 9mm round.

I have a Full size M&P 40 gun. I bought the Storm Lake 9mm and .357Sig conversion barrels. They both lock up tight and function 100%. I use 9mm magazines with the 9mm barrel/ammo and the .40 magazines with the .357Sig barrel/ammo. The Storm Lake conversion barrels are drop in and fit the hood of my .40 guns perfectly. I think this is the best way to go  vs using the 9mm factory barrel and getting more play in the hood area. The conversion barrels takes care of the sloppy lockup in the breach face area. The Storm lake barrels also give you better case support and are a match grade barrel.

Has anyone tried the new Apex barrels for Full Size and Pro models in the 40 slides? I think right now all they have is 9mm but there is a gunsmith fit model that might be just the ticket.

Just ordered a 9mm threaded barrel for my .40 VTAC.
Thanks for this thread Dog!