Other than carry ammo, I shot reloads exclusively through my G23 and G27. My favorite plinking load was Ranier 165 gr RNFP over 4 gr of Titegroup.
There isnt a modern firearm that doesnt have the "Not to be used with reloads/lead" warning.
Lead and reloading for the .40sw for use in a g23 should be easy. As many have said, keep your pressures low and make sure you realize the brass isnt going to make it through as many reloadings as the brass from some other guns (so always inspect your brass).
If you are worried about leading and the overpressure issue, just invest in a kkm/barsto/lonewolf and call it good.
I run my g23 brass through a redding GRx die to pull that glock bulge out. Its more or less just a precaution. I would post a link to one, but I am on my phone right now.
An aftermarket barrel (as others have mentioned) does a better job of supporting the brass than a stock barrel.
J&K I don't doubt that a g-17 can and does run lead. I see that the question was about .40 S&W, not 9MM. I don't know why but The lead .40s I have tried in Glock 22- 23s seem to really build up right at the throat, I haven't seen it to be that much of an issue in the 9mm. I have seen two Glock 22 kabooms and both were with lead ammo. Now I haven't noticed this phenominon with "black bullets or molly coated bullets, but bare lead yes. Perhapse your bullet alloy and quality far surpass Meister Bullet that was being used in the two I saw deflagrate. I have been wrong before! KurtM
can this be done in reverse? and use the same mags
convert to 40 cal that is?
You can convert a .40 Glock to .357 Sig and 9mm but you can't convert a 9mm Glock to anything other than a 9mm. The barrel hole in the slide is too small.
