I've used reloaded lead bullets in both of my XDs and they don't descriminate. They spit out whatever it gets fed...
Take note that the lead bullets I used were of good quality and they were assured they weren't too soft.
But it would be a problem with a Glock right?
It's contested that lead bullets shouldn't be used in polygonal barrels. Some have claimed no problems, but I wouldn't personally recommend it.
If you have a few bucks extra and still want the Glock, there are quality aftermarket rifled barrels for Glocks that are a drop in replacement at decent prices.