The 9X25 Dillon
The 9X25 Dillons origins come from an employee of Dillon Precision located in Arizona. In the 1980s Randy Shelley necked down the 10mm auto brass to 9mm trying to get as much slow-burning powder into the case as possible in order to drive a 9mm bullet to the velocity needed to qualify for the then IPSC Major Power factor of 175.
The result was the 9X25 Dillon. The 9X25 produced the needed velocity and a lot of gas to feed the compensators – enough that reportedly the pistols would dip rather than rise when firing. As a downside, this also caused large concussive blasts, meant faster component wear, and due to the casing size, the pistols had a lower magazine capacity. The lowering of the USPSA Major Power factor from 175 to 165 (160 for IPSC competition) leads to the demise of the 9X25 Dillon popularity in competition as the 38 Super would hit the power factor needed.
This 9×25 Dillon was made with just a simple barrel swap using a Glock 20 as the parent weapon. I ordered a stock length 9X25 conversion barrel from Lone Wolf Distributors and it dropped right in and I could still use the stock Glock magazines. Using it with the stock recoil spring was ok and worked although the recoil on hotter loads was sharp and it flung brass all over the place. I upgraded the recoil spring to a 20 pound Wolf spring and it helped immensely. Brass drops about 5 feet to my right and about 2 feet back consistently. The muzzle flip also resided a bit so I can get back on target quicker. Great upgrade for not that much money.
I have also had to upgrade the striker spring – after somewhere around 2500 round of the 9X25 Dillon and an uncounted amount of 10MM I was getting light primer strikes and misfires. Cleaning the firing pin channel very well and installing the new spring made the problems go away immediately.
As of this writing, it looks like lone Wolf does not have the same inventory of 9X25 barrels they previously did. I emailed them and customer service responded that they will likely feature more of them in the future as part of their Alpha Wolf line.
I also have contacted a few barrel makers and expressed an interest in having a 1911 barrel made chambered in the 9X25 Dillon. A few have said they have the reamers and it’s possible and for a decent price but I never found a 10MM 1911 I would sacrifice as a donor weapon for the project. The Rock Island Armory 10MM 1911 may become the start of that project sometime in the future.
Only two companies are currently producing factory loaded ammo for this round – DoubleTap Ammo and UnderWood Ammo. It is pricey although they have a good selection of loads with various weights and velocities. They always have something in stock on their websites. If you don’t want to pay about a dollar around there is always hand loading your own.
Before I get into the reloading information it needs to be said that this round needs attention to detail when reloading. It is a fun round but care should be taken. Previous experience reloading is not mandatory but highly encouraged for this round.
There is a ton of data floating around for this round at this time. Ramshot even responded to an email when I asked if they had any data for their powders – they were the only powder company to respond to my request for info and they included a few good loads that worked very well.
Some Ramshot data from their customer service people.
I have included what information I could find online over the years – it’s for your reference and is used at your own risk.
The reloading dies obviously come from Dillon Precision and is as per the usual flawless. The only addition I made was to add an RCBS 9MM expanding die to the set. This allowed me to bell the case mouth after necking the parent 10MM brass down to 9X25; I found I was crushing some of the shoulders when I was trying to load the brass for the first time. I attributed this to the tight neck made during the necking down process. After fire forming it seems easier to load each round but I still use the expander and then follow up with the crimp die to take any extra flare out of the brass before shooting, this round likes a solid but not overly tight crimp in my experience. A few thousand rounds later and I am still following the same procedure. Below is the video I made that is just a quick visual on how to for reloading the round.
I did experiment with and tried to use nickel plated casings since I had some on hand. It worked out ok and I managed to neck it down and load it without too much issue – but the first shot almost always caused a neck split so I just use nickel casings for 10MM loads now.
As a side note – Dillon Precisions customer service is top notch. I broke a depriming pin and could not find a replacement on their website so I emailed them. They asked for my address and without cost to me sent me a few extras and some bonus parts for the resizing die. Always great to do business with a company that takes care of its customers.
For my powder selection I am currently sticking with BlueDot, it meters well has consistent velocities and as a bonus creates huge fire balls when shot during the day and lights up the surrounding area at night as seen in the video that I put together. In addition, I can use it in loads for 3 different calibers so it’s very versatile for me. When I cannot find Bluedot on the shelves I work with Ramshot and it works just as well – although I only use it for the 9X25 Dillon.
9X25 Dillon with Bluedot
As hand loaders have experimented over the years reports of velocities of over 2000FPS using 90 or 95-grain projectiles have been made (and some factory loaded ammo is reaching those speeds). Although seating the smaller lighter bullets can be a hassle as the seating die has enough wiggle room at the cup holding the tip of the projectile that it allows the projectile to slide into the case at a slight angle. This causes the final round to have slightly off center projectile at best and can collapse the shoulder at worst. One person had a custom insert for the seating die machined that allowed them to seat the smaller bullets more easily. I wish I could find that person again to ask about having a second one made for my dies.
There are enough people loading and testing that the data can be found scattered around. Although some people are hesitant to share the hotter loads for fear of someone hurting themselves or people around them. I had a chance to chrono the 124 JHP projectile made by Precision Delta that I use as my standard bullet and it was north of 1500FPS in some loads. Precision delta makes some great projectiles and I have used them in a few different calibers. The heavier JHP is slower than the lighter weight projectiles but I started with it and it is accurate and consistent for me so I do not see a need to switch to anything else at this point.
As always if / when working with a hot load and outside of established load data be careful and work slowly up to your goal and watch for signs of pressure. I have a short bare-bones video explaining some of the reloading process and brass resizing. It is just meant as a quick visual aid for information.
In the end, this is a reliable, fun, loud, accurate round and if you reload – decently cheap. I always enjoy shooting it and it goes with me on every range trip. If there are steel plates to be shot than it will ring them with authority. I constantly have people come up to me at the range and ask about it, I am more than happy to let people shoot it and they come away surprised at how manageable the recoil is compared to how aggressive it sounds. Its bark really is worse than its bite if you have a firm grip. Although at indoor ranges you don’t make very many friends when you shoot it due to the concussive blast. I also use it as my carry weapon when camping. I have not used it for hunting but I can venture to guess that it would be great for a wide range of game.
One more video
Where to find everything you need…
-Ammo
-Barrels
– Reloading Dies
– Powders
Projectiles
https://www.precisiondelta.com/
How many grains of Blue Dot are you using? I’m up to 13gr under a 135gr Nosler JHP in 10mm (not 9×25) and getting the flames I crave. I’m just wondering if you’re stuffing more than that under the 124gr 9mm round.
So currently I am using 11 gr. During the day its noticeable at night its awesome. I would guess the lighter round is traveling faster allowing more powder to burn outside the barrel.
I’m thinking 🤔 of getting a 9×25 conversion barrel from lone wolf. My question is I would use the same cleaning tool as I would for a 9mm right? Thanks in advance keep up the great work
Yes it would be. All 9mm cleaning tools would work.
Hi sir how can I talk with you about this Dillon cartridge my email is XXXXXXX@gmail.com my phone is XXXXXXXXX tony Thanks
I shot you an email to see what I can answer for you
I am curious which shops had the reamer and headspace gauges.
I want to convert a 38 super barrel for my EAA Witness Elite Match 10mm to play with 9×25.
I have rechambered barrels for 357 SIG, but the 9×25 reamer and gauges are all custom orders and pricey.
I would love to find a shop I can send the gun and barrel to for rechambering.
I believe a few shops will build you a new barrel – https://kkmprecision.com maybe able to help you.