Sig Qs from Newbie

[Willard]

Guys,

I am getting interested in Sigs, and I have a few questions:

1) Are the calibers interchangeable between 9mm, 40 S&W, and 357 Sig? That is, can I just change barrels and mags?

2) Which 9mm models are available in SAO?

3) Which models are approximately a G19 size, but more narrow?

That's all for now, but I'm sure I'll have more questions. Thanks, all!

[8th SPS USAF]

1-You must start with 40/357 Sig to convert cals. You have to buy a 40/9
conv bbl from an aftermarket company. Barsto.
2- No
3-Yes 239-- 40/357Sig/9mm

[backbore]

1) On the 250 series yes. On the other series 8th SPS hit it with the 9mm conversion barrel from Barsto.
2) X5 is SAO. You can buy one from Top Gun. Here's a link to one, http://www.topgunsupply.com/sig-sauer-p226-x-five-tactical-9mm-night-sights-sao.html
3) The 228 is about the same size buy not thinner. The 239 is a good pick but there's also the discontinued P6/225 which is thin. There's also the chopped down 220's. 220 compact for instance is small and thin.