(4 customer reviews)

On Backorder

Looking to convert your Walther PPQ or P99 .40 S&W to 9MM? Look no further. With just the swap of a barrel and magazine you can start shooting 9MM out of your Walther .40 S&W. No other parts necessary.

Made from high strength 4140 Chromoly Steel, hardened to 40-44 HRC, this conversion kit will transform your Walther PPQ or P99 .40S&W into a 9mm in a matter of seconds. We have manufactured these barrels to the highest standards to ensure our customers have the greatest quality and most accurate barrel on the market.

A Walther PPQ/P99 9mm magazine MUST be used in order for the conversion to function. Walther PPQ/P99 .40S&W magazines WILL NOT WORK. We no longer carry magazines, but they can be purchased elsewhere at gunmagwarehouse.com and promagindustries.com.

Model * 

Factory Barrel Length * 

Barrel Options * 

Barrel Fit * 

Barrel Finish * 



Barrels listed as “In Stock” are machined per order specifications from customer.  Barrels are made drop in or fitted, cut to length, and crowned per order.  For this reason, please allow 2-4 weeks for your order to be filled and shipped.  If a barrel is listed as “On Backorder”, it means we are currently manufacturing a run of these barrels and do not have any in inventory.  You may place an order, which will place you on our backorder list, and we will fill and ship your order as soon as we are finished manufacturing.


For instructions on sending your slide, please click here.
Only slide is needed for barrel fitting.
Order number must be visible on outside of package when shipped.


We now offer custom PVD finish options.  Walther barrels are now available in our standard black finish as well as silver and copper PVD coatings. PVD (Physical Vapor Deposition) coatings are an extremely hard coating that offer aesthetically pleasing colors and increased lubricity.  Our CrN PVD coating is a silver finish similar to that of stainless steel.  Our TiCN PVD coating is a satin copper.  For colors, please see images at the top of the page.  PLEASE NOTE THAT PVD FINISHES ADD APPROXIMATELY 2-3 WEEKS TO LEAD TIME.


-Twist: 1/16
-Rifling: Conventional, button rifled
-Material: 4140 Gun Barrel Certified Steel
-Hardness: 40-44 HRC
-Crown: Recessed 20 degree target crown

Additional information


PPQ M1, PPQ M2, P99

Factory Barrel Length

4.2” Factory Full Size, 5” Factory Full Size, P99 Compact

Barrel Options

Standard P99 Compact Barrel, Standard Factory 4.2 Barrel, Standard Factory 5" Barrel [Add $10.00], Extended Length (Factory + 1 inch) [Add $10.00], Ported Length – Includes Porting [Add $120.00]

Barrel Fit

Drop In, Fitted – Slide Must Be Sent In [Add $45.00]

Walther Factory 9MM Magazine Quantity

None, 1 Magazine (15 Rounds) [+$34.99], 2 Magazines (15 Rounds) [+$68.99], 3 Magazines (15 Rounds) [+$102.99], 1 Walther Magazine (10 Rounds) [+$34.99], 2 Magazines (10 Rounds) [+$68.99], 3 Magazines (10 Rounds) [+$102.99]


  1. M. Sams

    I bought one of these barrels several months ago. I have both a P99 and a PPQ all bought LE surplus brand new, but I wanted to shoot 9mm. The Jarvis barrel fits both my Walthers better than the barrels that came from Walther! With the slide closed, if I try to move the barrel at the chamber, I can get a distinct click from the Walther barrels. I can’t budge the Jarvis conversion barrel. I merely ordered mine “drop in”. Now I’m considering ordering a .40 cal barrel to replace the nearly new Walther barrels!

  2. Ed

    Fixed Walther’s laziness.
    I got this barrel because my P99 is unreliable in .40. It randomly drops the mag under recoil with a verity of ammo and different shooters.
    Jarvis kept me updated every step of the way. When I got the barrel I was concerned because it doesn’t come with a recoil spring. However after putting a few mags through it I quickly realized that Walther had put a 9mm spring in my .40.
    I’ve had this barrel for a few years and have never had any problems with it.

  3. Timothy Kelly

    For years my P99 AS has functioned outstanding. Was allowed to carry it for service and having carried a 686 for 25 years I was use to the trigger pull. We were told “wheel firearms were no longer for service and was given a choice for a glock, sig and walther. Tested all the firearms recommended and well it was a toss up between sig and walther. They are all excellent firearms but only two I liked for the trigger pull and for staging was sig, walther. My choice was the P99 AS, as it felt more like my 686 trigger and I felt secure on the pull. The de-cocker also made it a no question either. Well this old patrol flat foot has retired, and 40s&w was more than I needed, so a Jarvis barrel was the choice. No mistake, it fell into the firearm and now my trips to the range are more fun with a low recoil. My only wish I could have had it back 40 years ago, would have made carrying a lot lighter.

  4. D.W. (verified owner)

    Like Ed, I owned a Walther P99 in 40 cal that regularly dropped magazines during normal firing… all 4 factory magazines, and it happened with different shooters, too. I decided to purchase the conversion barrel from Jarvis to fix the problem. This was a MAJOR improvement and forced my 40 cal P99 to abdicate the throne as my safe queen. I could hit the target with the 40, but the heavier slide, combined with the substantial thickening of the conversion barrel wall (almost a bull barrel!) increased the inherent accuracy of my pistol. I chose the barrel fitted to the slide option; nice and snug! I also replaced the extractor with the 9mm part; Jarvis says you only need the barrel and the magazine, but I felt a little better replacing the extractor, too. Had to wait about 2 months, but Jarvis kept me informed throughout the production process and came through, delivering the promised product. Thanks! No regrets from this reviewer. Well worth the price.

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