Are you asking what would be required to change from 9mm to .40?
I think you'd need a whole new top end. If that's what the X-Change kit does, that may be your answer. (I thought the 9mm 226 and the .40 226 had slightly different frames -- but could be wrong. Or it may be that the new .22 version of the 226 uses the .40 frame.)
The other direction is simpler -- going from .40 to 9mm just requires a "conversion" barrel and extra mags (and maybe a slide stop.)
February 21, 2012, 06:15 PM
Along with the caliber conversion kit (complete slide, barrel, recoil spring) you'll also need a .40 ejector.
February 21, 2012, 07:24 PM
Why an EJECTOR, too? Most guns with interchangeable slide kits don't require the ejector to be changed out.
February 21, 2012, 07:38 PM
This can be done on new late model P226s. The MK25 should qualify. You cannot do it with a older P226. I am not sure where the cut off is but it has to do with the locking block which was redesigned at one point.
You can go from 40 S&W to .357 Sig with a simple barrel change. You can use a conversion barrel like a Bartso to go from 40 S&W or .357 Sig to 9mm but not the other way around.
I understand where to buy the E2 grip from, but I should have been more clear in my original post. According to Top Gun Supply, to install the E2 grip, it:
"-Requires use of the new style mainspring 34280454. If you pistol has the long mainspring with a metal seat, you will need to also order the new mainspring. If you have the black plastic mainspring seat, you already have the correct mainspring.
-Also requires the new style trigger bar spring with the coil in the middle. If you have the plain curved trigger bar spring, you will need to replace it."
For the MK25, which of that applies or does not apply? I.E., can I buy the grip kit as is, or do I need to buy extra parts in addition to the grip kit in order to install it?
As for converting to .40 S&W, according to http://www.sigsauerguns.com/the-shop/accessories/sig-sauer-p226-40-caliber-x-change-kit/, it sounds like they are saying you can convert any caliber of a P226, "Convert your Sig Sauer P226 from .22LR Classic, 9mm, or .357 Sig to .40 S&W with this conversion kit."
I didn't know this was possible - I thought the same as to what those above have mentioned, that's why I wanted to double check. Seems no one really knows though lol.
February 21, 2012, 08:20 PM
Call Sig and they should be able to answer it directly.
The E2 grip should work because the MK25 should have the newer hammer strut.
February 21, 2012, 09:48 PM
I've mixed a couple 9mm and .357 P226s to get the slide and frame combo I wanted. No issues have come to light in a couple thousand rounds. The only caveat is that all my Sigs have been produced in the last 6 years.
The 9mm P226 ejector is slightly longer than the .40/.357, it'll work but I had issue with brass getting thrown into my face.
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