Do 9mm mags for Sig P229s work inside .40 229?

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Ignition Override

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Bought this first Sig (used) today. So solid, very smooth trigger.

In case somehow there is a nice price on a Used 9mm P 229 barrel somewhere, it would be nice to know whether the 9mm mags are designed to operate in the .40 Sig 229s.
 
You can't just throw a 9mm barrel in there. You'll need a conversion barrel. As far as mags locking in the frame yes I believe they will.
 
Ok thanks.

Now I see why it must be designated 'conversion. They are really pricey for the new one: $160-200 or so.

Have you recently read about any retail supplier for good, used (discounted) Conv. barrels?
 
Retailers for used barrels? Generally no. Best bet might be a private seller who no longer wants the barrel or other accessories. Maybe post a Want To Buy on the appropriate sections of some forums, or check out Gunbroker.com (but make sure they give a picture of the bore).


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Barrels are available from Sig from their web site, or from Top Gun Supply, but you'll need the proper recoil spring too. A call to the contact number for customer service is the way to go, they're very knowledgeable folks.

I have a P226 Mk25, originally in 9mm, then bought an "Exchange Caliber" unit in .40 S&W that works as well as the original 9mm slide/barrel assembly. It came with the barrel, recoil spring, and a .40 S&W magazine. Accuracy with the .40 upper is ever bit as good as the original 9mm upper.

On this particular pistol, with the .40 S&W upper installed, and using 9mm magazines, .40's feed and fire just fine and the slide locks back after the last round has been fired...in other words, no add'l .40 S&W mags were needed when I bought the .40 upper/barrel assembly. Can't say if that is universally true of all Sigs, but this one, a P226 Mk25 does.

I also own a Sig M11A1 (a P229) in 9mm. I just checked and all of my .40 S&W and 9mm P226 mags fit into the mag well on the M11. But I don't have a .40 bbl. and slide so I can't check for feeding issues.

HTH's & YMMV, Rod
 
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Instead of getting a 9mm kit for it ( unless you want one ) you can buy a .357 SIG barrel and drop it right in. You'll have a second gun in one for just the cost of a barrel, the mags are the same as a .357 SIG is a necked down .40 case.

That's what I did with mine when I had one, bought it originally in .357 SIG and then the .40 barrel. The thing that pissed me off was that no one other then SIG could answer my question about the conversion.
 
TunnelRat said:
You can't just throw a 9mm barrel in there. You'll need a conversion barrel. As far as mags locking in the frame yes I believe they will.
Click to expand...
I actually did just that, and bought a 9mm mag. It seemed to work just fine. Of course I may just have been lucky.
 
So there's a big caveat I missed above. Will what you did work technically? Yes. The 9mm barrel, if the dimensions are in fact different from the 40SW barrel, will be smaller than the 40SW barrel. That means it will fit in a 40SW slide. Is it advisable? That's where my caution comes in. If the dimensions are in fact different then the lockup will change and I'd advise against that. However, I poked around a bit and it seems that at least for some SIG models, the SIG SP2022 in particular and perhaps the newer P series pistols as well, some folks measured the exterior diameters of the 40SW barrels and compared them to the 9mm barrels and found them the same. Essentially SIG is using barrels with the same exterior dimensions and only changing the size of the bore. Assuming the rear of the barrel also matches in dimensions (SIGs use the barrel hood to lock into the ejection port) then maybe there is in fact no difference. However, I've read from folks that measured the barrels for P229s and did find dimensional differences both in the diameter of the barrel and the rear dimensions of the barrel hood. Then there's also a question of whether the locking insert on the frame will mate up correctly as well.

At the bottom of this webpage is a pretty long description of what will and won't work with regards to caliber exchange kits and you can ween from that some information about changes made to the pistols over time to make conversions easier and morseo, I imagine, to reduce the number of versions of parts.
http://www.sigsauerguns.com/accessories/conversion-caliber-x-change-kits/p229-conversion-kits.html
 
Thanks to all for the detailed, briefed info.

A large shipment of .20/rd., .40 cal. (S&W) from JGsales is being shipped as I ponder the options.
Also, a nice chunk of 9mm for the CZ PO1, possibly later also for this superb .40 cal. 229.

Instead of paying more for the .357 kit and .357 Sig ammo, it might be an advantage for me to work on more consistent shot placement, using much cheaper fodder, and get more tactical tng. (only had two days of it).

With better and more consistent tng., a gun in .357 Sig might then be able to harness the round's better potential. Being mostly a rifle guy, am somewhat new to handguns.
 
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dreaming:
Thanks for the link to the topic, and the excellent chart on using 'conversion' or regular barrels.

As soon as I rented both the 9mm and .40 229 (very similar, pleasant recoil), I began reading 'Sig Talk' quite often. And 'AKfiles' much less!
 
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