Lead in the Glock should be fine, especially in a 9mm. I really don't know what all of the hubbub is about shooting lead out of a glock barrel. I'm not saying that there aren't concerns. They just aren't directly related to lead.
What you should be concerned about is that 9mm is a high pressure round. Some loads get pretty close to the same amount of pressure generated in .357 magnum rounds. The problem with shooting reloads (not just lead, any reloads) in a Glock is that the stock barrel doesn't have a fully supported chamber and can't support a brass case that is in a weakened state from having been reloaded a bunch of time.
The fact is that kabooms can happen in many handguns, but seem to be happening most notably in Glocks. Of the reported kabooms in Glocks, very few of them were in 9mm's. The safe route to take is to just get yourself an after market barrel with a fully supported chamber.
Oh, another thing to watch out for, and one reason to be careful when shooting lead out of a glock is that lead reloads are dirty due to the lube/powder muck. If the chamber gets too dirty and the Glock won't go all the way into battery, you have to watch it, because Glocks will fire when they are slightly out of battery. If this happens, you'll likely get a kaboom.
The best thing to do is get a new barrel and do not get a reduced power recoil spring. The recoil spring is the only thing keeping a Glock in battery. If you can get away with a reduced power striker spring, that will also help to keep the gun in battery. It will also lighten your trigger pull, which is something that you may not want. I'd also use a powder that doesn't spike it's pressure. I think that you should avoid very fast powders like Bullseye, AA No. 2, etc. I use AA #5. It's a good middle of the road. When you go out to the range, just take a brush with you to clean out the chamber. You shouldn't have any leading problems with the projectiles. I've used a lot of them and have had no leading problems at all. Nothing that a few strokes of the brush won't take out.
This could happen whether you have a stock barrel or after market barrel.
