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

Federal 7Mm Backcountry Rifleman Review 2
Federal 7Mm Backcountry Rifleman Review 2

Federal Signs Agreement With U.S. Army to Improve Ammo Performance

Federal Ammunition announced this week that it has entered into an agreement that allows the U.S. Army to utilize its patented Peak Alloy ammunition case technology for use in multiple cartridges and weapon systems.

Four Armed Citizen Stories That Tell us a Lot

Each self-defense case is different. As we read them, we find ourselves wondering what we would have done, and then asking if the citizen made the best decisions possible in the worst-case scenario.

The Three Rs of Performance Shooting: Rise, Return & Realignment

Way back in the day, the three Rs of learning were colloquially known as "Readin’, Rightin’ and Rithmatic." In today's modern performance shooting, the three Rs become Rise, Return and Realignment, the core mechanics of recoil control.

Subsonic Ammo 101: Everything The Suppressor Shooter Should Know

Slower-than-sound rounds are an art as much as a science. For target shooting, bullet upset is not important, but if you’re using subsonic loads for hunting or self-defense, it becomes critical.

I Have This Old Gun: Model 1874 Gras Rifle

Following the Franco-Prussian War of 1870, the French military were in desperate need of a new service rifle. Their answer was the Model 1874 Gras, which was largely an update to the earlier Chassepot design.

Compact & Quiet: CMMG's ZEROED Banshee

CMMG has expanded its Banshee line of AR-style rifles with the ZEROED, a firearm that is optimized for suppressor use.

Interests



Get the best of American Rifleman delivered to your inbox.