9 mm Revolver Bores

by
posted on June 11, 2014
** 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. **
201089141944-sw_carry_m-1.jpg

A few years ago, I was deeply involved in persuading Smith & Wesson to build a particular model for the concealed-carry handgunners of this country. As many readers are aware, I am a big fan of the internal-hammer Centennial revolvers. I have been carrying them daily since the early ’70s and consider them to be the ideal concealed-carry handgun. Naturally, I was delighted when the company developed a light .357 Mag. Centennial, and I carry one of these every day. But, in a handgun world awash in 9 mm semi-autos, I felt-and still feel-that the company needed to offer a light 9 mm.

Thus began a series of experiments to prove that this might be a good idea. The firm did offer a stainless steel 9 mm Centennial at this point in time, but it was too heavy to expect habitual carry by all but the most dedicated. I ran a series of chronograph tests comparing velocities of the same basic gun in 9 mm Luger and .38 Spl. If you kept bullet weights the same-124 to 125 grs. and 147 to 150 grs. in both cartridges, the results were surprising. The 9 mm gun turned in faster speeds than the .38 Spl. Since the company used the same basic platform for both calibers, the shorter 9 mm round had a lot of freebore in the cylinder. I assumed that the reason for the velocity disparity was the so-called “jump” in front of the cylinder.

It may have been a contributory factor, but I am now convinced that there is another reason. I don’t believe the barrels on those early J-frame 9 mms were really 9 mms. I think they were .38 barrels marked 9 mm. The smaller 9 mm bullet was a looser fit in the larger bore and the velocity was therefore higher. And I also believe that this makes little difference in a short-range defensive handgun. A light 9 mm Centennial is still a good idea.

Latest

Ruger American Gen2 Patrol 1
Ruger American Gen2 Patrol 1

Review: Ruger American Gen II Patrol

Ruger's American rifle line represents a good balance between cost and performance, and the latest generation offers many welcome upgrades, as seen on this Gen II Patrol model in 5.56 NATO.

SOG Knives Celebrates 40 Years in Business

SOG Knives, which was established by Spencer Frazer in 1986, is celebrating its 40th anniversary in 2026.

The History of Repeating Arms Gun-Control Groups Don’t Want the Courts to Know

This episode of NRA’s The Armed Citizen Podcast refutes one of the biggest false claims gun-control groups and the politicians they support repeat ad nauseam by asserting that the Founding Fathers could not have imagined the AR-15.

Rifleman Review: Springfield Armory Kuna

Initially designed by Croatian manufacturer HS Produkt to fulfill a military contract, the Kuna has since arrived on U.S. shores through Springfield Armory as a semi-automatic, large-format handgun chambered for the 9 mm Luger cartridge.

All-American AK: The Bear Creek Arsenal BC-47

North Carolina’s Bear Creek Arsenal makes AR-15s, 10/22s and handguns, but new for 2026, it is introducing its first AK-pattern firearm with the BC-47.

Review: TNW Firearms ASR 1911

Reliable pistol-caliber carbines, especially with quick-caliber-change capability, are fun, and the ASR 1911 from TNW Firearms is one of the most unique of the bunch.

Interests



Get the best of American Rifleman delivered to your inbox.