SAAMI and +P

by
posted on September 22, 2011
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
wiley-clapp.jpg (2)

SAAMI stands for Small Arms Ammunition Manufacturer's Institute. It is an organization in which member companies establish standards for the production of all types of commercial ammunition. This includes the actual dimensions of a given round—width, length, case wall thickness, etc—as well as the pressure level to which it is loaded. When the SAAMI member companies agree to these yardsticks, gunmakers may proceed with building guns that can comfortably accept SAAMI-standard ammunition. Although handloading is an active and widely practiced adjunct to the shooting sports, no gunmaker will ever warrantee his gun when it is used with handloads. That's because they cannot exert any control over the way the ammo was loaded or what components were used. With virtually all commercial ammunition sold in America loaded by SAAMI members, the shooting public can proceed with their sport in relative safety. It is an excellent example of an industry regulating itself.

In the case of a few cartridges, the need for greater performance has driven SAAMI to create a so-called “+P” level of pressure. This simply means that the ammunition is loaded to a slightly higher pressure and is safe to use in guns rated by their makers to be strong enough to handle it. Some shooters are insistent on squeezing every last bit of velocity out of their hardware and this +P business is a controlled and safe way to get it done. But only a few cartridges have a +P standard and printing that mark on a box of hot-loaded cartridges of another type just won't do.

I have heard that .45 Colt ammunition loaded to high velocity and marked +P is available from several makers. The .45 Colt is an elderly cartridge, probably our longest-serving handgun round. Originally designed for use with black powder, the cavernous .45 Colt case will accept large charges of smokeless, which can destroy older revolvers. As loaded by SAMMI standards, .45 Colt ammo is on the mild side. Yes, I am aware that there are much stronger .45 Colt guns on the market, and some will take a great deal more pressure. But if higher pressure ammo finds its way into older guns, you have a recipe for accelerated wear and possiblydisaster.That's why there is no SAAMI standard for .45 Colt +P.

Latest

Smith Wesson Model 29 10 Facts 1
Smith Wesson Model 29 10 Facts 1

10 Things You (Probably) Didn't Know About The Smith & Wesson Model 29

Without a doubt, the Smith & Wesson Model 29 is one of the 20th century’s most shootable, collectible "superstar" revolvers. Here are a few little-known facts about the gun.

Packable Punch: Discreet Ways to Carry More Firepower

While folding and takedown firearms chambered for full-power rifle cartridges may be niche defensive tools, the dark situations in which they shine brightest aren’t going away anytime soon.

Southpaw Solution: Ruger Introduces Left-Handed American Gen II Ranch Rifles

Traditionally, Ruger has offered a range of left-handed rifle models for the southpaws among us, and now, the company's Gen II American rifles are available in a left-handed variant, starting with the Ranch models.

Gun of the Week: Kimber 1911 DS Warrior LW

In 2026, Kimber developed its 1911 DS Warrior, an American-made, double-stack design that is intended to be an affordable entry point into Kimber's double-stack handgun line.

The Armed Citizen® April 24, 2026

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

Spin Difference: The Impact of Barrel Twist Rates on Terminal Performance

When most shooters think of rifling-twist rates, they mostly think of rifles with their high BC projectiles, but the rpm of a bullet also plays a part in terminal performance.

Interests



Get the best of American Rifleman delivered to your inbox.