Shop for 40 Cal Ammo online at

40 cal ammo is for sale every day at You can buy this type of ammunition made by manufacturers such as Remington and Hornady through one of the many sellers listing their products here at, the world's largest gun auction site.

Getting to know 40 cal ammo

.40 caliber ammo features rimless, straight cartridges, which were originally developed at the behest of the FBI, which aimed to replace agents’ standard-issue revolvers with semiautomatic pistols in order to increase ammo capacity and reduce reloading times in the field.

The FBI specifically requested that Smith and Wesson produce a new handgun based on the existing Model 4506 .45 that could function with 10mm ammunition. By reducing powder in existing 10mm ammunition, thus providing more airspace in the case, S&W realized it could produce ballistics to match the FBI’s specifications. S&W then teamed with Winchester to produce the new cartridge, the .40 S&W.

40 cal ammo debuted in January 1990, but it was actually Glock that had the first commercially available pistols chambered to fit the new cartridges.

40 cal ammo specifications

The biggest difference between the 40 cal ammo cartridge and its parent case, the 10mm Auto, is the 40 cal ammo’s use of a small pistol primer and shortened length. The neck and shoulder diameter of .40 cal ammo cartridges is .423 inches. The base and rim come in at .424 inches with a thickness of .055 inches. The case is .850 inches of the overall length, 1.135 inches. The rifling twist is 1 in 16 inches.

Get your 40 cal ammo today

40 cal ammo is ideal for self-defense and is popular with law enforcement in the US, Canada and Australia. sellers update their auction listings frequently, so if you're looking to buy 40 cal or other pistol ammo, check back often.


Selected Filters

  • Accepts GunBroker Pay
  • Immediate Checkout - Credit Card
  • Layaway Available
  • No Credit Card Fee
  • Completed Items
  • Take a Shot
  • Sponsored On-site Listings
  • Showcase Listings
  • Charity Auctions
  • Has Pictures
  • No Reserve
  • International Shipping
  • Factory New
  • New Old Stock
  • Used
  • Price Range:
  • Barrel Length:
  • Caliber:
  • Capacity:
  • Frame Finish:
  • Gauge:
  • Grips:
  • Manufacturer:
  • Model:
  • Number of Rounds:
  • Number of Rounds For Sale:
  • Slide Finish:
  • Exclude Words:
  • Country:
  • State:
  • UPC:
  • Keywords:
  • Min Starting Bid:
  • Max Starting Bid:


Buy Format
$ to $
Listing Details
Item Condition
Show Only
Results for


Results for


Results for

{{currentKeywords}} in {{currentCatName}}

No results found or search too broad

Results for

40 Cal Ammo

1 Items Found
#11668827 Qty: 10+
Immediate Checkout * Credit Card Buy Now Available 3% Credit Card Fee