A look at two equivalent names that you"ll often uncover on the side of 45 caliber ammo boxes and also even firearms. Is tbelow anything you need to understand as soon as comparing ammo marked 45 Auto versus boxes of similar rounds noted 45 ACP?

It’s a common question among our customers as soon as looking at ammo for their 1911 or Glock 21 – carry out they need to be wary of 45 ACP vs. 45 Auto and vice-versa?

What’s the Difference Between 45 Auto and 45 ACP?

There is no distinction between 45 Auto and 45 ACP. They are in reality one and also the very same, which leads us to the point of this article: Some cartridges have even more than one name. Some have many type of, in reality, to the point wright here an inproficient shooter might wonder if they are ordering the correct ammunition.

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History of the 45 ACP vs. 45 Auto Cartridge


The cartridge referred to as .45 ACP (or .45 Auto) was designed by the great John Browning in 1904. The gunsmith produced the round for a new .45 caliber semi-automatic pistol that he was additionally developing for Colt. While Mr. Browning designed a good many firearms for his very own firm, he was not ungracious toward Colt whom he operated for too. He therefore didn’t object once his client made a decision to name their new round the .45 Colt Automatic Pistol, or .45 ACP for brief.

Shooters kbrand-new the round exclusively as .45 ACP for some time. But something amazing occurred 1926 with the starting of the Sporting Arms and also Ammunition Manufacturers’ Institute (SAAMI). The association of Amerihave the right to firearm, ammo, and component manufacturers exists to standardize the shooting sector. Their work-related is helpful: If you were in charge of Hornady, you would rely on SAAMI specs to make sure you’re turning out the same sized commodities as Federal Premium.

SAAMI Steps In

Other Names for 45 ACP

So currently we have a cartridge with 2 various names. To make matters more complex, the .45 ACP/.45 Auto is also well-known in Europe by its metric name 11.43×23 mm, in France especially as the 11 mm 43, and in Argentina as the 11.25 mm. It’s additionally sindicate called the 45 by shooters who describe it a lot.

So, not just is 45 ACP vs. 45 Auto the very same specific cartridge, it’s likewise the very same as 11.43x23mm or 11mm 43, or 11.25mm.

But Wait, There’s More!


The .45 ACP is not the only round with multiple names. Take the 9x19mm Parabellum as another instance. Georg Luger designed it in 1901 as the companion cartridge for his employer’s Pistole Parabellum. So, its name is fundamentally a metric measurement plus a trademarked name. SAAMI wouldn’t have actually that. So, they renamed it to 9mm Luger for their purposes. At the end of the day they’re still the exact same cartridge.

When purchasing ammunition, it is important to identify whether or not two differently called cartridges are identical. .38 Special and .38 Super both sound similar through optimistic words in their titles, but they are in reality nothing to do with one an additional. The .223 Remington and 5.56×45 NATO share the same dimensions, however the latter creates a significantly greater chamber pressure. The .300 Winchester Magnum and also the .300 Weatherby Magnum haven’t also gained the exact same parent casing.

If you are ever in doubt, a tiny time on Google will certainly set matters straight easily. For future referral you might additionally consult this table through some of the the majority of popular cartridges in America accompanied by their various other common names.

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Usual NameOther name(s)
.17 HMR.17 Hornady Magnum Rimfire
.22 Long Rifle.22 LR, 22
.22 Magnum.22 WMR, .22 Magnum, .22 WMRF, .22 MRF, or .22 Mag
.22 TCM.22 Tuakid Craig Micromagnum, 22TCM
.222 Remingtontriple deuce, triple two
.223 Remington.223 Rem
.223 WSSM.223 Winchester Super Quick Magnum
.30-06 Springfield.30-06, .30 Gov"t "06
.30-30 Winchester.30 Winchester Center Fire
.300 AAC Blackout300 BLK, 300 AAC Blackout, 7.62x35mm
.300 RUM.300 Remington Ultra Magnum, .300 Ultra Mag
.300 Win Mag.300 Winchester Magnum, 300WM
.300 WSM.300 Winchester Short Magnum
.308 Winchester.308 Win
.32 ACP.32 Automatic
.32 S&W.32_
.357 Magnum.357 S&W Magnum
.357 SIG357 Sig, 9x22mm
.38 Special.38 Smith & Weskid Special , .38 Spl, .38 Spc
.38 Super.38 Super Auto
.40 S&W.40 cal
.44 Magnum.44 Remington Magnum, .44 Mag
.44 Special.44 S&W Special
.45 ACP.45 Auto, 45
.45 Colt.45 Long Colt, .45 LC
.45 GAP.45 Glock
.45-70 Government.45-70, .45-70 Govt.
.50 Action Express.50 AE
.50 BMG.50 Browning Machine Gun, 50 Browning, .50 cal
10mm Auto10mm, 10mm Automatic
5.56×45mm NATO5.56 NATO
5.7x28mm5.7 x 28, 5.7
6.5mm Creedmoor6.5 Creedmoor, 6.5 CM, 6.5 CRDMR
7.62x39mm7.62 Soviet
7.92x57mm Mauser8mm Mauser, 8x57mm, 8 x 57 IS
7mm RUM7mm Remington Ultra Magnum
7x57mm Mauser7mm Mauser, 7x57mm , 7 x 57, .275 Rigby
9×18mm Makarov9mm Makarov, 9x18mm PM
9mm Luger9x19mm Parabellum