First, did you size the brass, and if so, did you get a full length size? Second, can you tell where the feeding issue is? Is it not chambering, is it catching as it comes out of the mag? Third, the Berry's copper plated bullets may not shoot in the Glock hexagonal rifling. Often times these copper plated lead bullets will tumble as they leave the muzzle if you run too long of a bullet. Check this to make sure.
Basically, you have to figure out why you are getting the failure to feed and where the round is catching. If the round has a heavy crimp, and it's flaring the case out and causing the round to be too large, then you will need to fix that. A final chamber check die on the last stage of loading will help this. If a round does chamber, but is a tight fit, once you fire the round, it will still be tight in the chamber causing your FTE issue. I would take a black Sharpie, and color up a few cases and chamber check them to see where you get scratches from it making contact. Don't feed them from mag. Insert them directly into the barrels chamber and let the slide go (safely, of course), so you don't scratch it before you chamber it.