Russ, I've seen quite a few Sig owner's pissed off because their Sig's frame rails have been chewed up by a .22 conversion kit. Let me give you some advice, buy a separate .22 and you will be much better off.
Look around on Sig Forum, there are plenty of examples of why not to put a conversion kit on your expensive SD/carry gun. I was in the market for one for my P229 SCT and there is no way I would put on on it now.
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