I am not 100% on this, but I think the way the SIG works is that you buy the SIG226 22LR and that frame will also take the centre fire slides and barrrels. SIG sells the conversion kit at a special, attractive price to those who bought the 22.
But, If you have a ordinary SIG226 in centrefire, the 22 slide and barrel won't fit. (I think this is correct.)
My son bought the Sig 22 LR first, and then a month later bought the 40 cal kit to go with it. I guess he could also buy the 9mm kit, too. That would be handy.
He got it from Questar, one of the sponsores. See banner at top of page. Nice people and good service.
Any SIG P226 will take the "sig 226 22lr slide"
The SIG classic 22lr is a normal SIG P226 frame with the 22lr adapter slide and barrel.


















































