Devereaux wrote:I would gather that I could buy an OEM barrel in 9mm for my 229 and it would work. But since I got that 228 kit you mentioned a bit ago, and have it working nicely, I guess I don't really need to do that.
I think a little confusion is starting to creep into this discussion. Hopefully, I can clarify here and help you and others that may be interested. To the best of my knowledge, the OEM barrel interchangeability applies only to the P224, P239 and P226. These models are interesting in that they were all designed and developed by SIG Sauer in the US of A. If you start with one of these three models in 40 S&W or 357 SIG, you can swap the calibers between 9mm, 357 SIG and 40 S&W using OEM barrels. You mention specifically the model P229, that is a different beast, in and of itself, and these statements do not apply to the P229 at all. Hence my recommendation that you pick up the P228 kit.
On the 226 end, I have 2; one is a 9 and the other is a .40 with a .357 barrel.
My research on the P226 tells me you can use the P226 9mm barrel in your P226 originally chambered in 40 S&W. You will want to use a 9mm recoil spring should you do that combination, but it should fit just fine and function perfectly for you.
Found that out when I tried to slide the 228 slide onto the 229 frame and it wouldn't go. Looking at it I noted that the locking lug part seemed different in the two slides.
This would be addressed by changing out the locking insert, the large block in the frame above the trigger and held in place by the takedown lever. Your P228 parts kit should have come with this part, you will need to install it into the P229 frame in order to utilize the P228 9mm slide.
I have never attempted to insert the 9mm barrel in the .40 slide, nor the other way around.
The P226 9mm barrel will fit and function in the P226 40 S&W slide with no part swapping involved other than the 9mm recoil spring. The 40 S&W barrel, however, will not work in the P226 9mm slide. The breech face of the 40 S&W slide is wider than the 9mm, the extension on the rear end of the 40 S&W barrel is wider than that of the 9mm and will not mate with the 9mm breech face.
Despite both being 226's, the .40 is a DAK, and somehow I view it differently. Not rational, I know, but there it is. I have contemplated getting the parts and putting in the DA/SA works into it, but have not done that. I realize it can be done, but am not sure I want to. The DAK, for all that I don't really LIKE it, is an interesting mechanism and worthy of being shot as is. It may be the best DA trigger out there for autos.
Whether the frame is a DAK, DAO or DA/SA has no bearing whatsoever on the interchangeability of the barrels per this discussion.
The DAK, for concealed carry, is by far my favorite SIG trigger. I don't care for the DA/SA trigger on the SIG's for a few reasons, this is a very personal choice and I will never call anyone out for not liking one of the SIG triggers or another, they are all fine. All my training has been with Glocks, going to a DA/SA manual of arms (MoA) would require, for me, unlearning everything I have learned with the Glock MoA and relearn the nuances of the DA/SA trigger. I don't care for the heavy initial, double action trigger pull of the SIG DA/SA trigger, it is in the 10# plus range. This, followed by the extremely light ~2# single action trigger pull, exacerbated by many by installing the Short Reset Trigger (SRT). I view the initial pull in any defensive scenario to be the most critical and want for it to be the most accurate. Yes, I could certainly train to overcome this deficiency in my performance, but I have other options available. Another aspect of the DA/SA trigger system is the need to decock any time you are in single action mode and no longer in a fight mode or need to reluctantly reholster. Again, something I could train to develop these skills, but I see no need.
The consistent trigger pull, whether the initial trigger pull or a trigger pull from the intermediate reset of the DAK trigger is much more to my liking and more closely resembles the trigger of my Glocks. We are truly living in the golden age of firearms, there is a trigger out there for just about any taste and skill level. My cup of tea is closer to the Glock trigger, just a personal preference that I won't force on anyone else.
Hope this helps clear some of the smoke around the issue.