.40 to 9mm conversion question

[Rastoff]

I just purchased an M&P .40S&W FS. I've read a few threads about converting it to a 9mm with a new barrel and magazine.

My question, for those that have done this, is, do you have any extraction issues? Since the 9mm is smaller, it would seem likely that the extractor on the .40 might not grab the 9mm as well.

 

[Rgoodwin]

Don't have one one but think the extractors are the same. Someone correct me if I'm wrong.

 

[S&W-Admirer]

I converted my .40 to a 9 with complete reliability. Both calibers use the same ejector and extractor if you look it up. The M&P is perfect for conversions. Just use a 9mm magazine.

 

[dfhawkins]

Go to Midway and order a full size 9mm S&W M&P barrel. They are presently in stock.

Smith & Wesson Barrel S&W M&P 9mm Luger

Keep your eyes out for some M&P 9mm magazines. They create seamless function through the last round.

44MAG.com - Smith & Wesson - Smith & Wesson M&P Magazine 9mm Fullsize 17 Round

No one seems to have them in stock now, but this is one place to check.

Don't worry about extraction problems... my experience and that of a great many on this forum is that the problem does not exist.

 

[Rastoff]

Thanks gents. The barrel is already on order. I just need to find a couple of mags.

 

[RCR24]

I just got back from the range with my my m&p 40c converted to a 9c with a factory barrel ordered from Midway. I used a full size 9mm magazine with extender so that it would fit the compact. I shot 100 rounds with no failures. Overall I'm pleased to have 2 guns for the price of 1 with the cost of the extra barrel. Only problem that I noticed is that I lost the white dot on my front sight. However, I don't think that this has anything to do with the barrel change.

 

[shoots]

9 Conversion

The 40 to 9 conversion is great. Two guns in one. The loss of the dot in the front sight is common. Get some white appliance touch up paint. Clean out the sight with alcohol to get oil out. And with a tooth pick apply the white paint into the front sight. Like a new sight without the trouble. Let us know how it worked for you.

 

[Jwiist]

Forgive my ignorance, I'm a little slow. When converted from 40c to 9c would one only want to use full size 9mm magazines in the compact, or could you use compact 9mm magazines in the converted 40c as well. I only ask because there is a chance I could trade my current 9c for a 40c and have a barrel ordered in the very near future. Sorry for the rambling, and by no means am I trying to hijack the original post.

 

[tectrry]

I have a 9c barrel in my 40c also and it has been flawless. I use one full size mag with a X-Grip on it and then i converted 2 of my FS 9mm mags into 9c mags by changing the baseplate to the special one with a finger rest made just for this reason (different from other baseplates). Midway sells them for $1.99.

I also have lost the white dot on two of my M&Ps and keep asking my daughter for her white finger nail polish - works great.

All of this was meant to say - yes you would want to use the 9c mags with your 9mm barrel in the 40c.

 

[Jwiist]

great news, thanks for clearing that up and I hope it helps Rastoff as well

 

[Rastoff]

Mine is a full size, but more info is always good.

 

[spoon22]

Is there a difference between the factory 9mm barrel and a conversion barrel, such as storm lakes??

I guess what i'm really asking here is if one will perform better then the other?

 

[bking]

I bought a 9mm barrel for my 40c and have great success. I bought one 9mm mag, but also found that the original 40c mags work just fine with 9mm rounds. Haven't had one to fall or fly out yet.

 

[tectrry]

Is there a difference between the factory 9mm barrel and a conversion barrel, such as storm lakes??

I guess what i'm really asking here is if one will perform better then the other?

From what I have heard the factory 9mm barrel is a couple of thousandths narrower than the .40 and therefore has a little play when you drop it into the .40 slide where the "replacement" barrels are made the same as the opening in the .40 slide. However, I've been told that because the barrel centers itself the difference doesn't matter (and has never been a problem for me). Then there is the difference in cost (the Storm Lakes barrels are twice as much as the stock barrels). There are many old threads in this forum that talk about it, but my summary of everything that I have read (and my own experience) is that the factory barrels work great and there is no need to spend the extra for a "replacement" barrel.

 

[S&W-Admirer]

I knew all of you were waiting for an update on the KKM 40-9 conversion barrel for my M&P .40 FS.:

Since the beginning of this thread, I have had ZERO reliability issues and excellent accuracy with the KKM 40-9 barrel with 9mm magazines. No unusual wear to the barrel or pistol.

I'm very pleased with the barrel. Seems like KKM isn't currently making the barrel since it is no longer offered on their website. Glad I got one when I did. Might still have a few if you call or maybe they will offer them again in the future.