Where is the best place to buy a conversion barrel for my 226 Legion.  I am wanting to change my 40 into a 9mm and also want a TB.  Who makes the best caliber conversions w/o breaking the bank?  And yes, I understand it will need fitting.

Your best bet is to buy a conversion kit. It's not about just buying another barrel and slapping it in. You also have to deal with magazines and a slide that has an opening for a .40 barrel and a .40 breechface.

Barsto makes a 9mm conversion barrel for SIG .40s but it's pricey.

In second thought, probably your cheapest option is to sell the .40 and just buy a 9mm version.

I was going to suggest the conversion kit also, but it does not look like they offer it in a threaded barrel.
You can get something like a Barsto barrel, they are $315.  the conversion kits are around $400.

People report using the .40 mags with 9mm, but if you want a reliable set up I know I personally would not trust that for other than strictly range use.  So figure on mags (about $25 each for Mec-Gars)
Ideally you would also replace the recoil spring.
I've read that the extractor may be an issue since it is trying to grab a rim that is slightly smaller (further away from the extractor).
You need a conversion barrel as the slide opening on the .40 is bigger than on the 9mm (ie. can't just put on a "normal" 9mm barrel)

For cost, I think the conversion kit is the way to go: new (proper) slide, spring, night sights (correct for 9mm) and a magazine.  That won't help if you want a threaded barrel ($230 from Sig).


Probably best to get the conversion barrel (Bar-sto etc), but I wouldn't rely on other than a range pistol.  Of course, if you shoot a few 100 rounds with no issues it may very well prove itself to be reliable.

I have a OEM Sig 9mm barrel and the OD is the same as the 40 barrel. I just bought 3 9mm mags and Im waiting on the 9mm recoil spring to try it. I have also read of people running a Sig OEM threaded 9mm barrel in a 40 slide on other message boards.