1911s – 45 ACP vs 9mm vs 10mm — Which is Best?

Caliber wars - 1911s, which is best, the 45 ACP, 9mm, or 10 mm?

The world of 1911s is quite broad and expansive. It’s one of the most popular pistols on the market, and with that level of popularity, it also comes in various calibers. This includes basically every automatic handgun caliber out there. The three most popular calibers of 1911s are the 9mm, the 45 ACP, and the 10mm. Which is best? Well, let’s take a look at all three.

1911s, which caliber is best? 45 ACP, 9mm, 10mm.

Why 9mm 1911s?

A 1911 in 9mm seems to be absolutely haram! But hear me out here fellas. 9mm 1911s are an excellent choice for new 1911 owners and even those who just appreciate the platform. 9mm 1911s do give you access to the cheapest centerfire pistol ammo on the market, and cheaper ammo means more shooting.

1911s - why the 9mm?

John Browning’s classic single-stack design is the most common magazine type in a 1911. This sucks for capacity, and every extra round you can fit into the magazine is a great accomplishment. A 9mm 1911 can often hold ten rounds in a flush-fitting magazine. That’s two more than 45s and one more than 10mms.

9mm for 1911s

The biggest reason to go 9mm for a 1911 is for the experience in shooting it. A full-sized 1911 in 9mm is a real joy to shoot. Recoil is minimal, so is muzzle rise, and the gun is just plain pleasant to shoot. You get all the great features and functions of a 1911 with reduced recoil and increased controllability. This makes it an excellent choice for self-defense from a practical perspective.

Why 10mm 1911s?

Oh man, I shouldn’t have to answer this. 10mm just rules. Well, that’s just me being a fanboy with no evidence or real reasoning beyond inherent bias. Unlike the 9mm, the 10mm round is an acceptable 1911 cartridge. Why wouldn’t it be?

1911s - 10mm

It outperforms both the 9mm and 45 ACP. The 10mm is a great choice for those looking for a hunting handgun or a brush gun for self-protection from animals. 10mm has been used to stop animals as large as bears. This caliber offers substantial power and penetration that’s beyond the 45 ACP and 9mm.

1911 10mm magazine

10mm 1911s also offer you a flatter shooting cartridge and only drops a mere 4 inches or so at 100 yards. This outperforms both the 45 ACP and 9mm range-wise and delivers some potent power. 10mm ammo also happens to be the most expensive of these three loads.

Why 45 ACP 1911s?

According to many, the 45 ACP is the Lord’s cartridges, and 1911s were originally made to chamber the 45 ACP. 45 ACP 1911s are much more common than the previous two cartridges, and this often opens up the market a bit, which lowers the cost of entry. On top of being the most common gun, it also sports the most common accessories. Finding spare mags, replacement parts, and everything else will be much easier with a 45 ACP 1911.

1911s were originally made to chamber the 45 ACP.

45 ACP 1911s tend to be easier to suppress due to the majority of the ammo being subsonic naturally. That makes it fun to throw through a can, and that makes the ammo easier to find when compared to 147 grain 9mm loads.

45 ACP 1911s

The 45 ACP as a defensive round is often overshadowed by the capable and higher capacity 9mm round. The 45 ACP is a bigger projectile, and with modern defensive ammunition, it does offer the most expansive ammunition. Some 45 ACP ammo expands to nearly an inch as it travels through a soft target.

Stack the Single Stacks

1911s are absurdly popular, and the fact that you can find a 1911 in 357 Magnum all the way to 22LR shows that there are options for everyone. There are lots of conversations that can be had about the caliber wars, but honestly, I think its best just to have all three.

1911 caliber wars - 45 ACP, 9mm, 10mm.

Travis Pike: read more of his articles.

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Travis Pike is a former Marine Machine Gunner, a lifelong firearms enthusiast, and now a regular guy who likes to shoot, write, and find ways to combine the two. He holds an NRA certification as a Basic Pistol Instructor and is the world’s Okayest firearm’s instructor.

  • john

    i like mine chambered in 38 super

  • Richard Snyder

    I am blessed to have 1911s in 380, 9mm, 357 Sig, 38 Super, 45 acp and 10mm as well as a Sig branded 22 conversion slide which works great with both the full-size and compact 1911s. I just swapped for a RIA 22TCM/9mm combo. When I say I am blessed, I mean it.

    • Robert Renstrom

      Blessed? You and me both as I have a few in 9mm, .45, 10mm at least one each as single stack and all bases covered in double stack. Life is grand! https://media2.giphy.com/media/iuXnKvwKtuqNq/giphy.gif

      • James Randall Adamakis

        What think you of the Kimber Ice?

    • disqus_P75F1IQr1N

      The RIA 1911A2 shares the Para and 2011 flaw of feeding 9mm from double-stack mags deeply ribbed to fit fat .45 frames. I have large hands and still find them unmanageable (I replaced one side with a thinner aftermarket grip and the other with skateboard tape).

      I wish a manufacturer would apply the EMP approach in double-stack, with a dedicated frame to accommodate a mag the size of the P-365 15-rounder; or maybe just move the rib on a single-stack closer to the top to allow 12 or so rounds.

    • James Randall Adamakis

      How is the TCM? Looks awesome, but I may choose the Ruger 57.

  • Patrick Moody

    I have both a Taurus 45ACP and a Colt Commander in 45ACP. I also have a Rock Island 10mm in 16 round double stack. It seems the author here forgot there are double-stack models of 1911 10mm out there also.


      I’ve been lookin at the RI 10 mm Double Stack. Whats your assessment of it?

  • Brian Swift

    I like my Dan Wesson fat boy point man1911 .45acp with a 14 round capacity with the factory match 7 twist barrel 3 inch group at 100 ft open sights……

    • James Randall Adamakis

      Daig. I would stay away from your field of 🔥.

  • pcb

    I have 45 and 9mm single stack, to solve the double stack mag problem I have a sti 2011 and yes we are blessed to have 1911s. John Browning was a great man.

  • 2ThinkN_Do2

    Another question to ask; Do you like Full Size, Medium, Compact or Sub-Compact, or: 5″, 4-4.25″, 3.5″ or 3″ barrel versions? Or all 4? My favorites are the middle two sizes. Cannot necessarily find anything other than 45 in less than Full Size, depending on the manufacturer.

    • Bigbigpoopi

      The 922’s threaded short barrel is a perfect suppressor host.

    • BraveNewWhirled

      I like my 1911s like I like my women: Medium with a little kick.

  • Bigbigpoopi

    I have an RIA tactical in .45 and the GSG 922 (3.whatever threaded d barrel and slide, full size frame). Love them both, but the 922 a bit more since it’s a nicer P22.

  • GlockandRoll

    This article gave me cancer… and then gave my cancer aids.
    I hope you are happy.

  • https://www.olamshrine.com Tuatha DeDanaan

    I don’t always carry a 1911.
    But when I do, I prefer it to be chambered in the cartridge made for it, not one it was adapted to.

    • daunt43

      A nice play on the Dos Equis commercial!

  • Lon J Loren

    I love my `1911’s because I’m a dinosaur. I have a Lightweight Commander one of the first one hundred produced in .38 Super. I have two Colt Govt. in .38 Super. To satisfy by need for a little more power I have a Long Slide 1911 in 10 MM. The .38 Super has been overlooked. It is a very powerful cartridge. On paper the .357 is more powerful. In reality the .38 Super is more destructive.

  • STEVE Lynch

    Rock Island has a commander size 1911 45 and 10 mm

    • Bear

      I stumbled across an RIA convert with 9mm and a very nice shooting TCM 9r barrels. The guy owning it didn’t like the difference in the 9 and the 22 barrel. Said the 22 was too intimidating. I love the thing . I almost giggled when I noted the fireball from the 9r barrel. And the 22 at around 2200fps ain’t all that disappointing either.

      • STEVE Lynch

        I saw one of those back before the pandemic, should have pulled the trigger, congratulations!!

  • Bear

    My Para Warthog with extended mag in .45ACP rocks bigtime. I just cannot stand leaving home without it.


      I too have owned a WARTHOG. It was a fantastic sidearm. BUT, the velocity loss from such a short barrel was unacceptable. You actually SEE the bullet as its flying! It was my dirt bike riding firearm, but I traded it for a Glock 29 in 10mm. Paired with UNDERWOOD EXTREME PENETRATOR ammo, you get a 140 grn bullet moving at a verified 1500′ per sec! The penetration of that round is mind blowing.
      Theres a reason why most in Alaska are trading their big cannon revolvers for the G20. It works!!!


    10mm is the best mm. The only reason to shoot 9mm is price and recoil. Don’t get me wrong, I have both. But recently, in this Pandemic time with 9mm goin for really stupid prices, I shoot my 10mm most as I have actually found local 10mm at less than $20 p/50. And having a CMMG BANSHEE ar PISTOL IN 10, I’m a VERY HAPPY CAMPER

    • James Randall Adamakis

      I have a g23, but have never shot a 10mm. Does your 10mm kick more like a .40s&w or .45acp?


        Are you trying to compare the G23 with the G29? A more powerful round will have its recoil amplified by shorter barrels. Don’t know that I can give you a good answer on that question, as I have not shot many short barreled 40. I have shot plenty of short barrel 45 and I would say that the 10 has a touch more recoil but not enough to keep me away. Honestly, it’s all about practice time and getting used to it

  • daunt43

    This was truly a worthless article as anyone who has been around 1911s for more than five years could have written this. No ballistic information at all!
    Using a word like “haram” makes me think you are Muslim. Muslim words do not belong in an article written for English readers.