Originally Posted by DannyR
If you are really going to do this to carry, then I suggest:
1. 9mm conversion barrel
2. change ejector
3. change extractor and spring loaded bearing.
Since the G27 is for carry, I doubt that you will be shooting it as much as your 9's, so why not just use it as it is?
This is the standard advice. However, I'm going to differ.
I use a lone wolf 9mm conversion barrel in my G27 for practice at the range (carry .40 or .357). That barrel has eaten and spit out every single round I've thrown at it. Over 600 rounds of JHP, FMJ etc. From cheap russian ammo through expensive carry ammo. No problems at all.
Quite frankly the G27 with a 9mm conversion barrel and a G26 magazine is more reliable than any of the Kahr firearms I've ever used.
So while the theory holds that all the other things need to be swapped, I'd test out the combination with your preferred carry ammo. Once you reach a roundcount that you are comfortable with... declare it reliable and carry away.
That is the exact same evaluation criteria I use for any firearm that is new to me... I run it through the ringer and if it passes my extensive testing, I trust it.