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 Mini-14 Upgrades
Ruger Mini-14 Upgrades

5 Must-Have Ruger Mini-14 Accessories

In production since 1973, the Ruger Mini-14 has spawned a rather healthy aftermarket of parts and accessories. Here are five that you really can't live without if you're a true Mini-14 fan.

New For 2026: U.S. Palm Eye of the Storm (EOS) Suppressors

Earlier this year, U.S. Palm promised to offer its own line of firearms and suppressors. Now, its line of suppressors, the Eye of the Storm (EOS) series, is finally here.

Gun of the Week: Taylor's & Co. TC73

The Taylor's Firearms TC73 has classic lines and a classic appearance, but unlike other lever-actions, this one has a few unique features.

The Armed Citizen® June 26, 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.

The U.S. Supreme Court’s Wolford v. Lopez Decision is Striking

In Wolford v. Lopez, the Supreme Court ruled that “Hawaii’s law prohibiting licensed concealed-carry permit holders from carrying handguns on private property open to the public without the property owner’s express authorization violates the Second and Fourteenth Amendments.”

The Fighting Shotgun: Myths, Legends & Facts

For a host of reasons, the Winchester Model 1897 "trench gun" probably never really made it into combat on the Western Front. But, the fact remains that Americans have always revered the shotgun as the ultimate fight-stopper.

Interests



Get the best of American Rifleman delivered to your inbox.