9mm Only. All of our Glock Barrels have fully supported chambers and you can shoot GOOD QUALITY reloads and lead bullets . If you buy a MT (Match Target) Barrel, it will NEED to be fit by a gunsmith. If you buy a SF (Semi Fit) Barrel, it may POSSIBLY NEED to be fit by a gunsmith. We do offer these fittings for an ADDITIONAL charge. All barrels shipped will require signature for delivery unless otherwise stated on the order form.