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

Glock Slimline Magazines 1
Glock Slimline Magazines 1

Review: Glock's New Slimline Magazines

Glock has finally introduced its own 15-round magazine for its slimline models G43X and G48.

Serious Sluggers: The Savage Arms 212 & 220 Harvesters

For hunters who rely on slug guns to fill their tags, Savage Arms has released updated models of its 212 and 220 Harvester bolt-actions.

Gun of the Week: Heckler & Koch G36 .22 LR

Due to Germany's strict firearm-export laws, along with U.S. firearm import laws, the closest any HK fan could get to owning a real G36 was in the form of the HK SL8. Now, though, Heckler & Koch has introduced its G36 .22 LR, which, profile-wise, is a G36 in all but chambering.

The Armed Citizen® July 17, 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.

Standing Strong for Colorado’s Law-Abiding Gun Owners Ahead of Critical Midterms

NRA EVP Doug Hamlin and NRA-ILA Executive Director John Commerford traveled to Denver this week to discuss gun rights.

A Visit to the New Smith & Wesson Academy

Let the training (re)commence at Smith & Wesson's new Academy in Tennessee.

Interests



Get the best of American Rifleman delivered to your inbox.