So now you have a G26/27, right?
To make it clear you can not make a 26 into a 27 but it will go the other way.
Yep and Yep.
So a G26 is a G26 ONLY
A G27 can be a G26 with a conversion barrel and 9mm mag, or G33 .357Sig with just a standard .357Sig Barrel and using the same .40 mag.
And G33 can be a G27 with a standard G27 barrel and the .357Sig mag.
Same Rules apply for the G17 and G22 & G31
Same Rules apply for the G19 and G19 & G32.
That's why I'd never buy a 9mm. I'd always buy the .40 or even the .357Sig if that's what they had in stock. Then if I wanted to shoot 9mm, I'd just get the conversion barrel and a couple mags.
And right now, the 9mm are so hard to find and when you do, like on Gunbroker, you'll pay more for a G17, G19, or G26 than you will a G22, 23 or G27. So if you're going to spend $100 more for the 9mm anyway, maybe as well get the .40, and for $129 get the 9mm barrel. It's just the wiser thing to do right now the way things are. Hopefully that changes after this gun debate BS is over.