Restarting my 9X25 Journey

[sqlbullet]

I have re-started working on 9X25 Dillon. I had last week off and worked with the cartridge during that time. Couple things I have learned and a couple others I have tested:

Brass process:

I selected fifty 10mm cases from my fired case pool. Ran them through my Dillon 9X25 sizing die with a bit of Imperial wax. Select your brass carefully if you are using fired brass. Any defect on the case mouth can result in a split case mouth during neck expansion/flare. I flared with a Lee universal flare tool.

Not sure why, but creating 9X25 brass makes the neck inside diameter excessively small. Doesn't happen when resizing fired 9X25 brass, but you will definitely need to run something like a Lyman M-Die or NOE neck die through brass after the initial creation of a 9X25 case from 10mm. I skipped this for the first 10 or so cases and, as the loading report and shooting results will show, there were problems.

Load Data

The only published load data I could find was from Lyman and did not include load data for many of the powders I had on hand to test. I turned to GRT and spent a fair bit of time there. I created a cartridge and chamber profile for 9X25 and created entries for my NOE cast bullets. Then I ran simulations for Power Pistol, Blue Dot, H110 and about a dozen other powder that I didn't end up creating test loads for. I will not be sharing my charge weights here. GRT simulations are not load data, and I am off book and potentially stupid here. If you want to join me in the stupid race, you can work up your own simulations.

Finally, Some Ammo!

I intended to load up NOE 360-128 SWC with Power Pistol and AA#7, 124 Grain HST pulls with the same powder, different load data, and NOE 360-150's with Power Pistol. In addition I had three each old test loads from some time back: Blue Dot with the NOE 150 grain and H110 with the HST's.

The first five NOE 360-128's loaded up without much fuss, but seating was more force than expected. At this point I had not (re?) learned that an M-die was needed. These loads were a disaster though I didn't know it yet - but they were not unsafe.

The powder charge for the Power Pistol HST's was just 0.3 grains higher so I charged those. First round seated fine. Second round split a neck. Third round crushed a neck, fourth round hooked the neck and crushed one side., fifth round seated. It was at this point I discovered the case had been sized very small so loading was suspended until I could locate my 35 caliber M die. During the neck crushing fiasco I also found that the HST's aren't suitable for 9X25 - Ogive is too long and you can't get a crimp that will prevent set-back. The H110 test loads work as it is a 100% case fill charge, but with Power Pistol they just slide right back into the case. I adjusted my COAL to 1.275" with the plan so single load just to get a data point for those two rounds.

And then it was time to leave with my grand total of 13 loaded rounds of ammo.

Shooting Results:

Shooting was with a Glock 20 using a 6" ported Lone Wolf barrel.

I fired the 150 grain Blue Dot loads first. GRT predicted these to be 1164 fps at my test load charge weight. Actual velocity for three shots averaged 1227.

Next up were the 124 grain HST's loaded with H110 predicted to be 1142, actual 1059.

The Power Pistol 124 grain HST's were expected to deliver 1353 (adjusted COAL included) and delivered 1344 fps - two whole shots tested.

Finally the Power Pistol 360-128 SWC cast bullets. I had high hopes for these since the HST's had performed so well. Simulation predicted 1356 fps, actual....726 with a 395 fps extreme spread. See? Disaster.

All the brass and primers look fine. No signs I was anywhere near serius pressure. Ejection ranged from anemic to tolerable, but nothing flung to orbit like 10mm brass is. Firearm function was 100%, even with those super weak loads.

Analysis:

During the short walk from my test range back to the cabin I stewed a fair bit on the 128 grain cast bullet loads. Those rounds only had 0.3 grains lesss powder than the HST loads, and had the bullet seated a fair bit deeper. Pressure, and therefor velocity, should have been very nearly the same. But the velocities I was seeing suggested 15-18K psi, not the 31K PSI the simulation predicted.

And then I remembered the tight necks. When I got home Sunday afternoon I grabbed an un-primed case and measured the neck ID - 0.344". I seated a 128 grain bullet, crimped it and then pulled it. Sure enough, that tight next was sizing my cast bullets down to 0.352". I hypothesize that such undersized bullets had no chance of actually sealing the bore and therefore didn't correctly build pressure, resulting in low and erratic velocity.

All my brass has now been through the M-die. I will be loading up a full cadre of 128 grain and 150 grain cast bullets with Power Pistol, AA#7 and 3N37 for my next outing.

[The_Shadow]

Here is what I do with mine, I size the casing for the chamber.  The Dillon dies can oversized and set the shoulder back too far and that can lead to case splits and neck separations.

I try to get the brass to be FLUSH to the barrel hood as possible 0.000" flush, but no more than 0.002" below the barrel hood.
This provides the proper spacing and helps keep the case neck splits to a minimum!

Understand the working the brass through the sizer induces work hardening (make brass brittle) therefore you will still see an occasional split or a casing that will not hold the bullets tight.

You will still need a 9mm neck expander or through the expander powder funnel to uniform the necks to accept the bullets.  I have used a RCBS 9mm neck expander with great success even loading cast lead alloy bullets.
Using bullets designed for the 357Sig or bullets with straight sides will also help prevent setback issues.  Some of the regular 9mm 0.354"- 0.355" bullets can be a loose fit or their radius noses extend too low on the bullet at their base to provide the best fit, seal and accuracy.  I have used some Jacketed bullets sized at 0.356" from Zero Brand bullets that were sold for the 38Super with good results.  I even tested a few jacketed bullets at 0.357" without issues.
Not all bullets are suitable for the short neck of the 9x25 as previously mentioned due to the ogive of some bullets...
I also have used my own cast alloy bullets sized to 0.3565" that have worked well.

[The_Shadow]

Here are the 9x25Dillon pull-downs https://www.10mm-auto.com/index.php?topic=2687.0

I had tested several different powders mostly with bullets under 130 grain.  CFE Pistol showed some good velocities with 115grain @ 1700 fps...

Had good luck using some of the 0.357" bullets from the 6" LWD in the G-20
The 110 grain 0.3570" is in the left two and then the 121 grain Zero JHP 0.3560" in the right two.