9 mm Revolver Bores

by
posted on June 11, 2014
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

Forehand & Wadsworth British Bull-Dog right-side view nickel-plated gun revolver with black grip
Forehand & Wadsworth British Bull-Dog right-side view nickel-plated gun revolver with black grip

I Have This Old Gun: Forehand & Wadsworth British Bull-Dog

Many eagle-eyed NRA members viewing the 1993 Western “Tombstone” no doubt recognized the Forehand & Wadsworth British Bull-Dog so deftly welded by actress Joanna Pacula, portraying Big Nose Kate, during a contemptuous card game between Doc Holliday and Ed Bailey.

Medal Of Honor Marine Receives Henry Repeating Arms Tribute

Henry Repeating Arms presented a Spirit of the Corps 250th Anniversary Tribute Edition rifle to Maj. Gen. Livingston for going above and beyond the call of duty on May 2, 1968, during the Battle of Dai Do in Vietnam.

Preview: Duramag 1911 DS Magazines

Duramag’s 1911 DS Magazines are compatible with numerous 9 mm Luger-chambered 2011-style handguns on the market.

Colt Monitor: The FBI’s “Fighting Rifle”

In the years between the World Wars, a rare variation of the Browning Automatic Rifle proved its reputation as an effective, devastating automatic rifle for combat between the country’s lawmen and its outlaws.

The Armed Citizen® May 19, 2025

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

Report Shows Inventory, Prices Have Dropped At Firearm Retailers

Nearly all gun and related gear inventories at retailers dropped in the last 12 months. So have most prices paid at the counter, according to the year-over-year comparison detailed in the latest RetailBI report.

Interests



Get the best of American Rifleman delivered to your inbox.