M&P 40 S&W to 9mm Conversion w/ KKM Barrel

[Jyezahn]

The 9mm oem barrel in my factory .40 has less wiggle than my .40 original barrel.

I'd like to purchase the .357 barrel. But I've yet to ever have seen .357 sig ammo ever! Where would I buy such?
Kmac

Well, whenever stock comes back up, Walmart, Cabela's, Bass Pro, etc.

 

[K.macocker]

Well, whenever stock comes back up, Walmart, Cabela's, Bass Pro, etc.

I've seen .22 .25 .32 380 9mm .40 .45 even .357 mag and .38 variants. But yet to ever see .357 sig.
Gonna ask if they have a slot for it at my local Walmart.
Thanks
Kmac

 

[uechikid]

Just get the barrel directly from S&W. It's about half the cost. Others sell conversion barrels because they can.

Yeah just. The problem is they are back ordered with no ETA.

 

[Jyezahn]

Yeah just. The problem is they are back ordered with no ETA.

And you are in a rush to blow your ammo downrange huh? Did you try to order one recently, or are you going off of info from a couple of months ago?

Either way, for most, it's not a problem to wait for a barrel because ammo is in such short supply right now. Plus, why pay nearly double for something just for semi-instant gratification that will sit in a drawer or safe for the most part until ammo becomes available. If it were me, I'd rather pay OEM price and use the savings to buy something else.

 

[S&W-Admirer]

My .40 S&W barrel is the one in the drawer. I am shooting more 9mm with the KKM conversion barrel because I have more 9mm ammo and reloading components.

Why did I pay more for a conversion barrel? - I can. It was available. It is an exact fit in the .40 slide. KKM makes great barrels - maybe more accurate than factory. I have more 9mm ammo than .40 available. The stainless barrel looks good in the all black pistol. I was able to find some new 9mm M&P magazines from a fellow club member for a reasonable price.

I'm glad some of you have had good results with the factory 9mm barrel. Nothing wrong with buying a conversion barrel.

 

[Jyezahn]

That's great, S&W-Admirer. Don't get me wrong, I don't think there's EVER anything wrong in buying aftermarket parts at all. In your case, it worked out well, you have the ammo, the magazines, and can reload. For others, not so much, so it's good for them to know that there are choices out there that will save them $, especially if they have to wait for magazines and/or ammo.

 

[bob42]

9C barrels are in stock as of 30 minutes ago. I called S & W direct and placed an order and rep. said it was ready to ship now.
Bob

 

[S&W-Admirer]

10 more quick rounds through my KKM 40-9 conversion barrel this afternoon after I finished teaching a CHL class. Flawless performance. Excellent accuracy. I'm using 9mm magazines.

 

[Bret]

9C barrels are in stock as of 30 minutes ago. I called S & W direct and placed an order and rep. said it was ready to ship now.

What's the price? Did they have 9mm magazines available too?

 

[Jyezahn]

What's the price? Did they have 9mm magazines available too?

Price is listed in post #11 above. Highly unlikely that they have any magazines right now.

 

[Bret]

Price is listed in post #11 above. Highly unlikely that they have any magazines right now.

Thank you!

 

[S&W-Admirer]

Forgot to mention in my first post that the KKM 40-9 conversion barrel was a drop in fit.

 

[Jyezahn]

Forgot to mention in my first post that the KKM 40-9 conversion barrel was a drop in fit.

You mentioned that in the last line of your original post. The stock barrel from S&W is also a drop in.

 

[Rowlette]

Just to let you all know, I have 357 MPC and drop in SW OEM 9mm and .40 barrels. Also purchased 2 9mm full size mags for ease for range use and 2 extra .40c mag which I color coded the barrel and mags to avoid loading mistakes. Oh yes absolutely seems that I purchased 3 different weapons and the ability and choice of ammo.
My EDC is the .357 SIG MPC Rowlette

 

[semperFi]

Can you convert a 9mm to a .40?

It may not matter much, but the 40-9 conversion barrel fits the M&P slide and breech face exactly. The factory barrel does not but is close enough. The conversion barrel may be more readily available for purchase as well. The M&P pistol is ideal for conversion since the 40 S&W and 9mm ejector and extractor are the same. Other pistols, like Glock, require a 40-9 conversion barrel to fit the slide.

Can you do a 9mm to a .40 with a new barell and a new mag?

 

[S&W-Admirer]

No. Not easily. You could buy a 40 barrel and remove a very small amount of metal and make it fit. See the 9 to 40 Shield threads for information.

 

[S&W-Admirer]

After all the ribbing for buying the KKM conversion barrel on this thread, I feel better after reading about all the accuracy problems with the factory 9mm barrel, especially the older ones. The KKM barrel locks up real tight, is excellent quality and has a better twist rate for the lighter bullets. By the way, KKM isn't listing M&P barrels on their website right now. The brushed stainless barrel looks great in the all black pistol. No regrets.

 

[S&W-Admirer]

Shot 50+ rounds of Remington, Winchester and two different handloads through the 40-9 KKM conversion barrel. Feeding was 100% and accuracy was excellent when I did my part. The pistol shoots to the point of aim. BTW, the KKM barrel has the older style barrel design with the collar. The factory .40 barrel that came with the pistol has the newer design without the collar. Test fire date 12/12. The KKM barrel is the same diameter all the way down the outside the barrel unlike the slight cone design of the muzzle end of the S&W factory barrels. The trigger seems to be getting better each time I make a trip to the range.

 

[S&W-Admirer]

Shot another 25 rounds of reloads through the KKM conversion barrel from a rest. Accuracy was excellent. Feeding and ejection were 100% with 9mm magazines.

 

[rbas]

New to this but looking for conversion as well

Hi all, I was looking to get a new M&P 40 but would like the ability to shoot 9mm due to cost of .40 ammo. I called S&W and was told that there 9mm barrel wouldn't work without modification due to misalignment of head plus any such work would void there warranty. So I asked about KKM barrel and they again said it would void warranty. I asked why don't S&W make an factory conversion kit but was told that most people would rather just buy 2 guns. Seems to me there would be a big demand for such a conversion kit from S&W. Some people may not want to buy both a 9mm and .40. At this point, I'm looking at a new Glock because they do offer a conversion kit that doesn't void there warranty from what I've been told. Sad, I may have to add a Glock to my collection which to this point has all been S&W.