9.8 mm or 9.65 mm?

by
posted on January 22, 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. **
wiley-clapp.jpg

The first decade of the 20th century saw a lot of developmental effort in the handgun field. It’s well known that legendary designer John Browning was involved in both American and European firearms design. In 1910, he had all but completed-with Colt and Army Ordnance-the development of the Government Model .45 pistol. Mr. Browning was also working with FN, the national arms plant of Belgium, and had used essentially the same design as the Colt. There were several different Colt pistols that had an FN counterpart. This was done with the approval of all concerned, because the two companies agreed not to sell arms in the others territories. They had literally divvied up the world and everything was working fine.

But they had omitted a few countries, which were open to competition. Romania, down in the Balkans, was such a place. Colt got wind of a Romanian interest in some kind of medium-bore auto. They developed and produced a scaled-down version of the soon-to-be famous 1911 pistol.  In so doing, they created a collector’s item, the 9.8 mm Colt. Only a few were made, because Colt salesmen were unable to sell the Romanian buyers on the gun.

Aware that this was going on, FN came up with a version of the same pistol. Once again, they were unable to sell anyone on the idea and the guns never went beyond the production prototype stage. They used a cartridge called the 9.65 mm Browning. All of this was well recorded in several respected sources. I once saw one of the Colt pistols at an NRA Convention, but was not allowed to handle it. I have never seen the FN gun or the ammo for it. The whole concept is very interesting to me, but the ammunition is even more so. If Colt and FN made essentially the same gun, why did they use two different cartridges?

It looks like they didn’t. The 9.8 mm Colt and 9.65 mm Browning are (nominally) .15 mm different in size. In English measurement, that is about .0059-fifty-nine ten thousandths-of an inch. That really is not much. As a matter of fact, it’s just about the difference between bore diameter and groove diameter. I would bet serious money that this was the difference between the 9.8 mm Colt and the 9.65 Browning. One company named its round on bore diameter, the other on groove. There is no real difference.

Latest

IHTOG Lee Metford 1
IHTOG Lee Metford 1

I Have This Old Gun: The British Lee-Metford Rifle

In the late 1880s, the British military adopted its first bolt-action rifle chambered for the .303 British cartridge. This is the Lee-Metford, the first step on the way to the iconic Lee-Enfield.

Colt Delivers M4A1 Rifles to Guatemala Through Foreign Military Sales Program

Guatemala’s military recently acquired more than 2,000 Colt M4A1 rifles through the U.S. government's Foreign Military Sales program as part of the country's ongoing military modernization efforts.

Going Pro: Springfield Armory's Echelon Pro Comp

Springfield Armory has expanded its Echelon line of handguns with several new Echelon Pro Comp offerings, bringing a number of what the company calls "performance-oriented enhancements" to the platform.

Steel Yourselves—Metal is Back

These days, it’s safe to say that injection-molded polymer of some sort is the most prevalent material from which to construct a pistol frame, but lately, that trend seems to be reversing. Metal is back.

NRA-ILA Names National Shooting Sports Foundation Official Partner of the 2026 NRA Gun Bus Battleground Tour

This sponsorship through NSSF’s Protect Liberty PAC puts the firearms industry trade association on the road through Election Day.

Ori-gun-i: The ZEV Technologies FDP Carbine

The American art of folding polymer and steel into a working firearm reaches what might be its zenith with the Zev Technologies/Magpul FDP.

Interests



Get the best of American Rifleman delivered to your inbox.