During the late ’80s to the early ’90s, both firearm manufacturers and ammo suppliers were scrambling to create the next high-performance pistol cartridge.  The FBI Miami Shootout would shift the agencies focus from their current duty revolvers to magazine-fed semi-automatic handguns.

What Changed?

In 1990 the FBI decided on a new caliber, the .40 Smith & Wesson.  By shortening the 10mm auto, the 40 S&W was easier to grip and control. Its shorter case length also allowed it to fit in most of the standard frame 9mm semi-automatics of the time.  In 1994 the Swiss-German firearms manufacturer SIG Sauer would attempt to enhance the performance of the .40 S&W.  This was done by necking down the .40 S&W case to accept 9mm bullets. These higher velocity rounds, dubbed .357 SIG, were able to match the performance of 357 Magnum revolvers of that era.

To this day both the .40 S&W and .357 SIG are carried by law enforcement agencies.  However, there is one round that has seemingly gone unnoticed.  The 9×25 Dillon.

Approaching Mach 2 With A Glock

The Origins

In around 1987 an employee of Dillon Precision named Randy Shelley wanted to create a cartridge that would meet the IPSC Major power factor of 175.  To accomplish this task, he necked down 10mm brass to accept 9mm projectiles.  This new case paired with a slower burning powder was able to give him the velocities he needed.

Left to Right: 9mm, .40 S&W, .357 SIG, 10mm Auto, 9×25 Dillon

While the Dillon would see use in competition, it was eventually edged out by .38 Super.  During this same time, during the early ’90s, the .40 S&W and later the .357 SIG would be introduced.  It seems the Dillon had lost its place in the spotlight at just the wrong time.

Where it shines?

Approaching Mach 2 With A Glock

Three things make the 9×25 Dillon intriguing, and this Glock 20 serves as the perfect example.

1.  Ease of Use.  All that’s needed to shoot 9×25 Dillon is a barrel for your Glock. In minutes you can be shooting this caliber using the same 10mm Glock mags.
2. Velocity.  The Dillon can fire 90 gr ammo at 2,100 ft/s.  Borderline rifle performance out of a Glock.
3. Recoil.  With the projectile weighing far less, there’s less felt recoil compared to a 10mm Auto.

The Verdict

Approaching Mach 2 With A Glock

To this day, this remains one of only two handguns that I’ve personally seen in this caliber.  A select few companies make guns, parts, and ammunition for the Dillon, but they’re few and far between.  Personally, I would love to see 9×25 Dillon comeback, I just don’t see it coming into fruition.

Still, a part of me can’t stop thinking about how cool a 10MM FBI MP5 would be in this caliber.

Big thank you to James Rose at Park City Gun Club for letting me shoot this gun, and for sending over these fantastic photos.