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

Doug Midwayusa Visit 1
Doug Midwayusa Visit 1

A Cathartic Journey Back to Midway Arms & the MidwayUSA Foundation

NRA CEO & EVP Doug Hamlin returned to MidwayUSA, a place he first visited decades ago in the early 1990s as publisher of Guns & Ammo magazine alongside the late, great Robert E. Petersen.

Review: Steiner MPS-C

The new Steiner MPS-C is the compact but rugged, closed-emitter optic we’ve all been waiting for.

The Truth About Bans on Glocks

Gun-control groups are again trying to ban one of the best-selling and most iconic semi-automatic pistols ever—yes, most Glocks.

WOOX Expands Operations in America’s Woodworking Heartland

WOOX, manufacturer of Italian-American made gunstocks, axes and knives, is breaking ground to expand its operations in Hickory, N.C.—where woodworking expertise has been passed on for generations.

Beyond the 1911: Wilson Combat's New Bulwark

The Bulwark is designed as a “hard-use service pistol” that combines the best features of a 1911 with those of a daily-carry duty gun, and Wilson Combat delivers it all at a price point below Wilson’s traditional handgun offerings.

Rifleman Review: Walther Arms PDP Pro-X PMM

Recently, Walther Arms has combined several PDP feature sets with a Parker Mountain Machine compensator to produce the Pro-X PMM.

Interests



Get the best of American Rifleman delivered to your inbox.