A look in ~ two similar names the you"ll often find on the next of 45 caliber ammo boxes and even firearms. Is there anything you should understand when comparing ammo significant 45 Auto versus boxes of similar rounds significant 45 ACP?

It’s a usual question amongst our customers once looking at ammo for their 1911 or Glock 21 – do they need to be wary of 45 ACP vs. 45 Auto and vice-versa?

What’s the Difference between 45 Auto and also 45 ACP?

There is no difference between 45 Auto and 45 ACP. They space in reality one and also the same, i m sorry leads us to the allude of this article: some cartridges have an ext than one name. Some have many, in fact, to the allude where an inexperienced shooter may wonder if they room ordering the correct ammunition.

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History that the 45 ACP vs. 45 Auto Cartridge


The cartridge called .45 ACP (or .45 Auto) was designed by the good John Browning in 1904. The gunsmith developed the round for a brand-new .45 caliber semi-automatic pistol that he was likewise designing because that Colt. If Mr. Browning design a great many firearms for his very own company, that was not ungracious toward Colt whom he functioned for together well. He because of this didn’t object once his client decided to surname their new round the .45 Colt automatic Pistol, or .45 ACP for short.

Shooters knew the round specifically as .45 ACP for part time. But something interesting happened 1926 through the founding of the Sporting Arms and Ammunition Manufacturers’ institute (SAAMI). The association of American firearm, ammo, and component manufacturers exist to standardize the shoot industry. Their work-related is helpful: If you to be in charge of Hornady, friend would count on SAAMI specs to make sure you’re turning out the very same sized commodities as federal Premium.

SAAMI procedures In

Other Names for 45 ACP

So currently we have actually a cartridge v two different names. To make matters more complicated, the .45 ACP/.45 Auto is additionally known in Europe through its metric surname 11.43×23 mm, in France specifically as the 11 mm 43, and in Argentina together the 11.25 mm. It’s additionally simply dubbed the 45 through shooters who describe it a lot.

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

But Wait, There’s More!


The .45 ACP is no the only round v multiple names. Take it the 9x19mm Parabellum as another example. Georg Luger designed the in 1901 as the companion cartridge for his employer’s Pistole Parabellum. So, its name is basically a metric measurement add to a brand name. SAAMI wouldn’t have that. So, they renamed it come 9mm Luger for your purposes. In ~ the finish of the job they’re still the very same cartridge.

When purchase ammunition, that is essential to identify whether or no two differently named cartridges are identical. .38 Special and also .38 at sight both sound similar with optimistic words in your titles, however they are in reality nothing to perform with one another. 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 got the same parent casing.

If friend are ever before in doubt, a small time ~ above Google will collection matters directly quickly. Because that future referral you may likewise consult this table with some of the most well-known cartridges in America accompanied by their other usual names.

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Common NameOther name(s)
.17 HMR.17 Hornady Magnum Rimfire
.22 lengthy Rifle.22 LR, 22
.22 Magnum.22 WMR, .22 Magnum, .22 WMRF, .22 MRF, or .22 Mag
.22 TCM.22 Tuason 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 blacksmith & Wesson one-of-a-kind , .38 Spl, .38 Spc
.38 Super.38 supervisor 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 lengthy Colt, .45 LC
.45 GAP.45 Glock
.45-70 Government.45-70, .45-70 Govt.
.50 activity Express.50 AE
.50 BMG.50 Browning maker 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