.357 barrel conversion for Walther P99?

bigdude01 · November 3, 2010, 05:22 AM

I currently own a P99 AS .40 cal (pictured below). I want to convert it to a .357 sig. Where can I purchase a barrel? Bar-sto no longer produces Walther barrels.

ShipWreck · November 3, 2010, 06:08 AM

I don't think ya can, sorry. The P99 never picked up much aftermarket support

RamItOne · October 8, 2012, 06:53 PM

Been searching for a while and keep striking out. Anyone have any insight?

lechiffre · October 9, 2012, 09:24 PM

Good luck.

.357 SIG barrels for the P99 are rare, but they are out there.

10-96 · October 11, 2012, 12:27 AM

I remember pondering on that some years back, and I think I may have stumbled upon the reason for the lack of that conversion... via Sig Sauer. Ok, first- the P99 slide is pretty light, as far as slides go- right? Now lets back up to the end of the Sig P228- Sig and various other folks wanted to chamber the .357 Sig ctg into a P228- no, I think it was all about the .40 S&W. Well, it wasn't a happy marrage either way. The P228 had a light stamped steel slide that was on the light and narrow side. The speed of the recoil couldn't be slowed down without adding springs that made manipulating the slide all but impossible. Too fast and harsh of a recoil beat the pistols to death The solution was the birth of the machined P229 slide which was both heavier and wider. The extra weight and width allowed retardation of the movement without sacrificing firearm life.

So that's the hypothesis I came up with- it's just too hard to convert to .357 Sig without giving up too much lifespan of the pistol.

Fishbed77 · October 11, 2012, 09:54 AM

Quote:

I remember pondering on that some years back, and I think I may have stumbled upon the reason for the lack of that conversion... via Sig Sauer. Ok, first- the P99 slide is pretty light, as far as slides go- right?

The .40S&W P99 slide is a different design than the 9mm slide. It is heavier and can easily be recognized by the lack of the angular bevel (which serves the same purpose as front cocking serrations) at the front of the 9mm slide.

RamItOne · October 11, 2012, 10:21 AM

Still no luck
Bar-sto and Jarvis both made them a good while ago. Walther just doesn't seem to have much of an aftermarket.

Fishbed77 · October 11, 2012, 03:12 PM

That doesn't surprise me. To be honest, the P99 is one of those pistols that's just WAY better in 9mm than .40S&W in my opinion (kind of like the Browning High Power).

However, with the increasing poularity of the PPQ (which is the same pistol as the P99 with a different trigger group, and whose barrel is interchangeable), there is always the possibility that the conversion barrels might be re-introduced. It might be worth writing a letter to Bar-sto or Jarvis.

Sharpsdressed Man · October 11, 2012, 05:21 PM

The barrel manufacturers mentioned above quit making them for two reasons. First, not many sold. Second, there were reports of damage and short weapon life due to the increased slide velocity and recoil impulse of the higher pressure (.357SIG) round. The barrel makers decided it wasn't worth a lawsuit, and the manufacturer (Walther) wasn't ever going to recommend or endorse it. You CAN do it, just shoot it sparingly, or use reduced loads for practice.

November 3, 2010, 05:22 AM	#1
bigdude01 Junior Member Join Date: March 7, 2010 Posts: 6	.357 barrel conversion for Walther P99? I currently own a P99 AS .40 cal (pictured below). I want to convert it to a .357 sig. Where can I purchase a barrel? Bar-sto no longer produces Walther barrels.

October 8, 2012, 06:53 PM	#3
RamItOne Senior Member Join Date: May 24, 2011 Posts: 990	Bump Been searching for a while and keep striking out. Anyone have any insight?

October 9, 2012, 09:24 PM	#4
lechiffre Senior Member Join Date: February 3, 2008 Location: phoenix,az Posts: 513	Good luck. .357 SIG barrels for the P99 are rare, but they are out there. __________________ if God hadn't meant us to shoot he wouldn't have given us trigger fingers do the interns get glocks ?

October 11, 2012, 12:27 AM	#5
10-96 Senior Member Join Date: October 19, 2005 Location: Tx Panhandle Territory Posts: 4,159	I remember pondering on that some years back, and I think I may have stumbled upon the reason for the lack of that conversion... via Sig Sauer. Ok, first- the P99 slide is pretty light, as far as slides go- right? Now lets back up to the end of the Sig P228- Sig and various other folks wanted to chamber the .357 Sig ctg into a P228- no, I think it was all about the .40 S&W. Well, it wasn't a happy marrage either way. The P228 had a light stamped steel slide that was on the light and narrow side. The speed of the recoil couldn't be slowed down without adding springs that made manipulating the slide all but impossible. Too fast and harsh of a recoil beat the pistols to death The solution was the birth of the machined P229 slide which was both heavier and wider. The extra weight and width allowed retardation of the movement without sacrificing firearm life. So that's the hypothesis I came up with- it's just too hard to convert to .357 Sig without giving up too much lifespan of the pistol. __________________ Rednecks... Keeping the woods critter-free since March 2, 1836. (TX Independence Day) I suspect a thing or two... because I've seen a thing or two.

November 3, 2010, 06:08 AM	#2
ShipWreck Senior Member Join Date: November 9, 2005 Location: Texas Posts: 1,744	I don't think ya can, sorry. The P99 never picked up much aftermarket support

October 11, 2012, 10:21 AM	#7
RamItOne Senior Member Join Date: May 24, 2011 Posts: 990	Still no luck Bar-sto and Jarvis both made them a good while ago. Walther just doesn't seem to have much of an aftermarket.

October 11, 2012, 03:12 PM	#8
Fishbed77 Senior Member Join Date: November 23, 2010 Posts: 4,862	That doesn't surprise me. To be honest, the P99 is one of those pistols that's just WAY better in 9mm than .40S&W in my opinion (kind of like the Browning High Power). However, with the increasing poularity of the PPQ (which is the same pistol as the P99 with a different trigger group, and whose barrel is interchangeable), there is always the possibility that the conversion barrels might be re-introduced. It might be worth writing a letter to Bar-sto or Jarvis.

October 11, 2012, 05:21 PM	#9
Sharpsdressed Man Junior member Join Date: June 21, 2009 Location: NE Ohio Posts: 1,176	The barrel manufacturers mentioned above quit making them for two reasons. First, not many sold. Second, there were reports of damage and short weapon life due to the increased slide velocity and recoil impulse of the higher pressure (.357SIG) round. The barrel makers decided it wasn't worth a lawsuit, and the manufacturer (Walther) wasn't ever going to recommend or endorse it. You CAN do it, just shoot it sparingly, or use reduced loads for practice.