9×25mm Dillon

9x25mm Dillon - Image via Wikipedia

CriticalAn IPSC Wildcat

The IPSC has been responsible for the creation of many different wildcat cartridges, with the 9X25mm Dillon being one of them. This cartridge was developed specifically for use in competition shooting and was initially created by an employee of Dillon Precision to compete with the .38 super cartridge. Ultimately, the 9x25mm Dillon would have twice the case volume of the case that it was supposed to be competing against, yet with this advantage changes in the IPSC rules negated many of the advantages and competition of the 9x25mm Dillon had in the sport shooting world. While many notable shooters used the round during its heyday, this failed to save the cartridge from being limited to a strong but small following. Currently only a couple of high performance ammunition manufacturers create factory ammunition for the round.

A Wildcat To Dethrone The King

9x25mm Dillon
9x25mm Dillon – Image Source Wikipedia

Sometime around 1987 two employees of Dillon Precision Randy Shelley and Eric Harvey created the cartridge with the specific desire to propel a 9mm bullet at the speeds necessary for the round to compete in the Major Power Factor of the IPSC. For the original requirements of the Major Power Factor, a 115 grain, 9mm bullet needed to be traveling at more than 1500 ft./s to qualify for the competition. Fundamentally the 9x25mm Dillon is essentially the 10mm case necked down to accommodate the diameter of a 9mm bullet. With this design the cartridge was able to achieve a case volume of roughly twice that of what the IPSC shooters favored cartridge, the .38 Super had. Due to this increased case volume, shooters were able to “feed” their compensators more gases and thus, in theory, further reduce muscle flip. However the higher pressures produced ended up doing too much to compensate for muzzle flip and some shooters felt that the downward pressure from the muzzle brake was hard on elbows and shoulders. Despite this the 9x25mm Dillon cartridge was still able to propel a 115 grain bullet at about 1800 ft./s and impact with well over 800 foot pounds of force. Making it an excellent round for IPSC competitions and self defense as well.

The best way to look at this cartridge is to consider the 9x25mm Dillon as analogous to the 10mm much the same as the .357 Sig is to the .40 S&W. Ultimately the round is capable of providing performance similar to that of the .357 Magnum while vastly increasing the capacity when compared to a six shot revolver.

Despite this it was a series of factors that ultimately relegated the 9x25mm Dillon to its status today. First and foremost, due to safety concerns, the power factor needed to qualify for the Major Power Factor was reduced to 160. This negated the cartridge’s ultimate advantage when compared to the .38 Super, with its far higher pressures and 10mm parent case, not only did the 9x25mm Dillon have a lower magazine capacity the parts of a 9x25mm Dillon handgun tended to wear out faster than those chambered for a lower pressure cartridge. Meanwhile .38 Super loadings only improved further over the years and the 9x25mm Dillon retained small following but ultimately has not retained the same level of popularity as the .38 Super. Between the .38 Super being a more popular competition round, and its parent case, the 10mm, being arguably a more powerful and more popular round, few shooters have found a compelling reason to move away from more popular cartridges to this sleeper round.

 

Loading Data

Two major manufacturers produce ammunition for the 9x25mm.

The first is Underwood Ammo offering a number of selections from light extreme penetrator, 90 grain, pure copper rounds flying at 2000 ft./s and the muzzle energy of 800 foot pounds of force to 125 grain, standard jacket hollow points, traveling at 1700 ft./s with 802 foot pounds of force at the muzzle.

Secondly Doubletap Ammunition also offers a number of factory ammunition loadings as well. Their lightest loading is an 80 grain, lead free, hollow point flying at 2120 ft./s with an energy of 800 foot pounds out of a 6″ barrel. Their heaviest offering is a 147 grain full metal jacket wad cutter, flying at 1495 ft./s with an energy of 730 foot pounds of force, also out of a 6″ barrel.

For those looking to hand load this particular cartridge Dillon Precision still offers pistol die sets for hand loaders looking to experiment and reload with this cartridge.

Bullet

Primer

Powder

OAL

Velocity

90gr HP-XTP Hornady

CCI 350

12.2gr LongShot

1.26

2050 fps

100gr FMJTC Fiocchi

Fed 215

16.2gr AA #9

1.252

1780 fps

100gr FMJTC Fiocchi

Fed 215

16.5gr AA #9

1.252

1860 fps

108gr JSPOG Zero

Fed 215

14.9gr AA #9

1.268

1666 fps

115gr FMJ Winchester

Fed 215

14.3gr AA #9

1.268

1556 fps

115gr FMJ Winchester

Fed 215

15.1gr VV N110

1.268

1547 fps

115gr FMJhp Winchester

Fed 215

15.1gr VV N110

1.268

1547 fps

124gr FMJfp Hornady

Fed 215

14.2gr VV N110

1.268

1443 fps

124gr FMJfp Hornady

Fed 215

12.2gr AA #9

1.268

1443 fps

130gr FMJ Hornady

Fed 215

13.3gr VV N110

1.268

1369 fps

130gr FMJ Hornady

Fed 215

11.9gr AA #9

1.268

1376 fps

Chambered Firearms

Being primarily a competition cartridge the 9x25mm Dillon is most commonly found in a 1911 style pistol, however other pistols originally chambered for a 10mm round can easily be converted to the cartridge, normally by simply changing out the barrel. Outside the 1911, the Glock 20 and Glock 20 SF are two types of handguns that are easily converted over to the caliber. This makes finding holsters and other accessories relatively easy for handguns chambered in 9x25mm Dillon. While there are manufacturers currently producing factory ammunition for this round, there are no production pistols available making adopting this cartridge difficult and more time-consuming than other, more standardized, cartridges. Magazines designed for the 10mm cartridge are needed for the round, however with 10mm production pistols readily available finding magazines for your pistol conversions should not be difficult. Below you can see the guys over at Gunblast talk about this great round.

Not As Popular As It’s Dad, but Still Good

Once it lost its advantages in the competition shooting world, shooters found little reason to adopt it as a defensive round. Despite this it could be an excellent defensive round, able to throw a 115 grain bullet at 1800 ft./s impacting it over 800 foot pounds of force,

This “bigger .357 Sig” has untapped potential as a hunting and defensive handgun caliber, despite no longer offering competition shooters the advantages that it once did. Despite this potential, none of the 9x25mm Dillon’s features have managed propel it to a place of popularity with anyone outside of it small yet devoted following.