Hope you enjoy tinkering. Springs, ejectors, extractors, and some minor fitting by qualified gunsmith may be required. Most things are seldom truely “drop in” and shoot. I’ve enjoyed all my Glocks bone stock. My favorite is the Glock 21. Of the entire stable, it’s the most accurate, and most fun to shoot just as it came from the box.
Not really. In all of the aftermarket barrel swaps I've seen on Glocks about the only additional thing that may need changing is the recoil spring, and sometimes the guide rod.
My G21 has been an excellent gun and is bone stock. I've never had a single problem with it.