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Sig 229 40S&W conversion to 9mm.

1941 Views 7 Replies 3 Participants Last post by  twoguns
I have a Sig 229 40S&W with a Sig conversion barrel to .357 Sig.
The magazines say 40/357 on them and both calibers shoot without any problems.
I have also tried 9mm's in them and they fit good.

Bar-sto sells a special barrel to convert a Sig 229 into 9mm that is different from the standard Sig 229 replacement 9mm barrel.
I am thinking about ordering one for $200. from Bar-sto but would like to get some feed back from anyone who has one.
I am only concerned with the 40 to 9mm conversion barrel and not the Sig 229 9mm pistol.

I have other 9mm pistols, but the accuracy of the Sig with both the .40S&W and the .357 Sig are so good I would like to see how it shoots with a 9mm barrel.
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Howdy Mr. Arcman,

I have a 9mm down/converstion barrel that I use in my stainless steel P226R purchased in 357 Sig, that functions flawlessly. I simply use a 17 rd Mec-Gar 226 9mm mag for all 3 calibers (357, 40, and 9mm). The 9mm down/conversion barrel is different for a stock 229 barrel, as it is made specifically to hae the same outer diameter as the 40/357 Sig barrels, so it will fit properly in your slide.

The barrel I have was purchaed from EFK Fire Dragon, and was a straight drop in with no fitting required. I have this barrel and his 357 Sig conversion barrel for my FN HP 40, and both are true drop ins. They were both a bit cheaper as well, somewhere around $150.00. I own one Bar-Sto barrel that I obtained for 357 Sig to convert my CZ75-B 40 to that caliber. While I orderd the semi-drop in, my CZ gunsmith has stated that it is going to require some extensive fitting as it in not a drop in. So just a suggestion sir, you might want to take a look at the EFK 229 9mm down/conversion barrel as well. I feel both of my EFK barrels are far more accurate than I can be too.

The only thing I have noticed is that if I were going to shoot a ton of 9mm rounds, I would probably want to swap out the recoil spring to one designed for 9mm rather than using the same spring installed in my pistol for the 357 Sig / 40 rounds.

Hope this helps a little sir.

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Dear Arcman: Once many years ago while wandering about the desert I came across Bar-Sto and had to have a BBL for my M1911. Still got it and have one in my BHP-35 and one for my Glock 34 as well. Probably I would have them on my S&W revolvers but I don't. All of the barrels I have needed a degree of fitting by competent hands. Young Mr. Stone will do that for you if you send them the slide I think (it has been a while). Now, be advised that when you get your barrel it will be very, very tighly chambered and may well object to reloads - just my experience! Hope to help like TGs!
Thanks Guys,
I have done barrel fitting and built a few 1911's and worked for 40 years in a machine shop as a welder and machinist.

I have the barrel on order at dealers pricing.
It is special order and takes up to 12 weeks.
My real concern was how it shoots and if the 40/357 magazines function or should I order 229 9mm mags, but I'll wait to get the barrel first.

I use a 15 lb. spring in my Beretta 92 and a 16 in my 96, so I will order a lighter spring since my 9mm reloads are light target loads.

The magazines work perfect.
The Sig 40/357 12 round mags hold 14 rounds of 9mm's and feed as reliable as the other calibers.
Howdy Mr. Arcman,

Glad to hear that your existing mags will work with the 9mm rounds. I have found Sig mags to be very user friendly in my experience. I have a ton of the Sig factory marked 40/357 P226 mags, as my agency required "factory" mags for duty use. But I discovered that the MG 17 rd 9mm mag functioned fine in that pistol using all 3 calibers. Plus I get one more round capacity of 40 and 357 than the factory mags give.

Once you have the barrel and have been able to shoot it, please share your thoughts with us.

Howdy back Twoguns,
Here is what I posted on another forum about the barrel fitting.

It only took a little filing on the front barrel lug to let the slide go completely into battery everything else was a perfect fit.

Bar-sto's tolerances are so close the head spacing is perfect.
The chamber is the tightest of any of my 9mm's and so tight I found my RCBS carbide sizing die wasn't doing it's job.
Factory ammo fit perfect, but reloads were so tight in the chamber I needed to change to my Lee carbide sizing die to fix the problem of full length sizing to the rim.

Feeding was perfect using my Sig 229 .40/.357 12 round magazines. They held 14 rounds with no trouble.

Accuracy was good using cast and jacketed bullets last night.

Going to the range now to try more cast bullet loads and brag about the versitility of this pistol.
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Howdy Mr. Arcman,

I am really glad to hear that the barrel is working out so well for you sir. If you are not already using one, you might also want to consider using a Lee factory crimp die as the final reloading step too. It will apply a nice crimp and resize the round back to factory specs at the same time.

Enjoy you new pistol. I have all 3 barrels for my stainless 226R built on a steel frame, and I do understand what a pleasure shooting all three calibers in one pistol really is too.

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