Can I use 45 auto ammo in xd 45 acp?

.45 auto ammo is .45 acp the acp stands for Automatic Colt Pistol, the original .45 auto was developed in 1911, and is still a very much respected sidearm. Do not, however attempt to chamber and fire .45 cal. cartridges made for use in revolvers - these are a different case family, lack the extractor groove, and depending upon length, can cause dangerous blow-off of case head. The 45 ACP dimensions are: Case mouth - .473 Case base - .476 (Right above the extractor groove.) Rim - 480

45 colt revolver case: Case mouth - .480 Case base - .480 Rim - .512

.45 ACP cartridges Type Pistol Designer John Browning Specifications Case type Rimless, straight Bullet diameter .451 in (11.5 mm) Neck diameter .473 in (12.0 mm) Base diameter .476 in (12.1 mm) Rim diameter .480 in (12.2 mm) Case length .898 in (22.8 mm) Overall length 1.260 in (32.0 mm) Primer type Large pistol Ballistic performance Bullet weight/type Velocity Energy 230 gr (15 g) Hydra-Shok JHP 900 ft/s (270 m/s) 414 ft·lbf (561 J) 185 gr (12.0 g) JHP 950 ft/s (290 m/s) 371 ft·lbf (503 J) 230 gr (15 g) JHP 850 ft/s (260 m/s) 369 ft·lbf (500 J) 165 gr (10.7 g) JHP 1,060 ft/s (320 m/s) 412 ft·lbf (559 J) Test barrel length: 5 in Source: Federal Cartridge

For the revolver cartridge, see .45 Colt, Revolver