I have a P229 Legion in 40 S&W. Sig Sauer sent out a legion email today advertising their fancy legion slides, but only in 9mm. Which got me thinking...

https://www.sigsauer.com/rx-sl...-p229-romeo1pro.html

Could I purchase a barrel (it'd probably be a threaded barrel and I'd purchase a can for it), throw it in this slide from sig, and have a rapid change out 9mm conversion for my P229 legion? I carry my P229 legion every day, and a quick conversion could have merits.

Obviously I'd need magazines...but the question is if there is any difference in the frame from 40 to 9mm on the P229?

What'd be real cool is if the P226 legion romeo slide would slap on there...

Swap slides and go.
I do it with my 229 9mm, swap in a .40 slide and go shoot.

P229-1 frames are the same for all calibers. But you will need to get a p229-1 9mm locking block, a factory 9mm barrel will not work with the 40/357 block. Fitment of the 9mm barrel in the 40 slide I am unsure of, ass well as if the recoil spring will allow for correct function.

The recoil spring would stay with the barrel in the slide...but changing out the locking block would be a wrench in the plan. At that point, I may as well just setup a new frame, or pick a different platform.

THANKS GUYS!

I appreciate the quick answers.

The 229-1 and the 229 .40 use the same locking insert.
Early 229's and the 228 will need to have the locking insert swapped.

An easier swap would be to get a BarSto conversion barrel 40-9 and drop it in. Get some 229-1 9mm mags or actually any Sig P series 9mm mags and you are good to go. I only own 2 229-1 mags and use my MecGar or Sig regular 9mm mags all the time.You can change out the recoil spring to a 9mm spring if needed. I run +p factory and hotter reloads and just use the 40 cal spring.