38 caliber revolver ammo
The glock 21 fires the .45 automatic colt pistol (.45acp, or .45 auto) round.
Federal premium ammo
No
.40 S&W with JACKETED bullets. The polygonal rifling in a Glock does not mix well with lead bullets.
No - they are very different cartridges.
TMJ (Total Metal Jacket) bullets should be safe in a Glock with polygonal rifling. It IS fully jacketed ammo. Glocks do not do well with cast lead bullets.
http://www.glockfaq.com/gunsmithing.htm#slideframe The 23 receiver is not compatible with the 38 slide.
9x19mm, also known as 9mm Parabellum or 9mm Luger.
No, and you shouldn't even use. 38 Special ammo in it, either. If it was made in the 1800s, it was probably chambered in .38 Long Colt, and that is the only ammo which is compatible with that revolver.
NO
.38 special Stay away from the "+P" ammo