[veprx4]

G20, 4.6"LW bbl, Speer .355" 125gr TMJ, WIN primers, PP powder
Using barrel as headspace gauge...cases flush with barrel hood over the chamber. Best effort had 8 out of 10 rds fired. FTF rds looked like above pic. Light primer strike. I am experienced reloader. Never had this issue even with .357Sig. Have tried dialing the sizing die back and forth to set the shoulder for proper headspace. As far as I can tell the headspace seems correct, but I keep getting FTF w/above primer strikes. Dillon dies used throughout. Have used 90gr XTP projectiles and 9x25 DT and resized 10mm brass. OAL running 1.285" with the 125gr pills. Where am I going wrong?
TIA for any help you guys can provide.

 

[veprx4]

veprx4, How dow the barrel fit in your slide? Does it move front to back any when in lockup condition? If it slides any while it is in lockup then the movement, that would change the strike at striker impact causing a soft hit.

With your magazine and chamber empty assemble the pistol while the open muzzle is pointing to the ceiling, place a pencil inside the barrel eraser down, against the breech, squeeze the trigger to release the striker, the pencil should jump up fairly high if the striker is hitting with force.

Be sure to check that the safety plunger is in the correct orientation in the slide as that could interfere with proper strike function. The plunger channel needs to be clean of lube and debris for proper function of the plunger & striker.

If all of that checks out, headspace is very critical to the proper alignment of the casing with respect to the breech face and under the extractor hook.

Case sizing needs to be less than 0.002" inside to flush for best fit. When testing in your barrel, be sure to push on the casehead, to seat it inside the chamber as far as it will go, while looking at the headspacing. Do this with an empty sized casing without a bullet to check things to eliminate the bullet or case neck as an issue.

COAL should be 1.250"-1.260" to have good neck tention on the bullets to help elimenate setback of bullets.

Good luck getting things sorted out!

mrpipesmkr, no I haven't had the chance to work with the 800X in the 9x25 yet, but I will visit that soon! Just a few things going on taking precedence...sorry!

Tks for the feedback. Barrel lockup is fine. Have already tried pencil test. No problems there. Took slide apart and cleaned the striker and channel thinking that grime was the problem. It wasn't. I swapped out the striker assembly from my G21 to my G20 and will try it again at the range tomorrow. Taking all the unfired rds and will run some through again. I will check the headspace per your advice. I figured either OAL or headspace or both are causing my problems. Very frustrating, because I'm used to having very reliable reloading results. I'll post again after the range trip. Tks again.

 

[veprx4]

Veprx4,
I agree with everything Shadow says, but would add some things I experienced.
Dillon factory loads had way too much set back on the shoulders for my LWD chamber. Be sure you are sizing to your chamber (as I believe you are) and when checking headspace be sure you round is fully seated in the chamber.

During bullet seating the short neck and shoulder of a 9x25 can be distorted which makes for a tight fit in the chamber. Over crimping will cause a swell in the neck which can prevent full chambering.

I switched to a Ghost 3.5# trigger set up on my G20 and got a few light strikes on 9x25 (none on 10mm) . If i remember correctly, the Ghost kit came with the 4# striker spring and after I put the factory Glock spring back in the problem was eliminated. Also, with the light striker spring installed the trigger safety would not re-set after I took up slack on the trigger and released it, creating an un-safe condition.

If you havn't already done so, I would suggest a 20# or 22# recoil spring in your G20. I run a 22# in mine and when I installed it I experienced a more positive lock up and even improved accuracy. My belief is that the heavier spring helps to overcome slight variations in headspace caused by things like fouling in the chamber, insuring that the barrel fully locks up.

Don't give up on the 9x25. It's a great round and about the most fun you can have with a pistol!

Tks for your feedback. My G20 was bought used at a local show a year or two ago. Running a DPM recoil reduction system with their recoil guide and spring...don't recall the spring rating. Also has the 3.5 connector with factory spring. Today I ran 11 test rounds through the pistol. Only 3 of 11 fired on the first trigger pull. Good solid strike on fired rounds. I cycled the remaining rounds by hand letting the slide ease gently into battery. All rounds fired second time around. A range staffer looked at the headspace and thought it was a tad below the chamber hood. He recommended dialing back the sizing die a bit more, so the loaded round would require a light push into the chamber versus dropping right in. This supported his theory of the rounds going off when slide eased into battery. He reasoned the not quite properly headspaced rounds were going too far into chamber by the normal slide recoil force. I will adjust sizing die back a bit more and try again next range visit. Tks for your help.

 

[veprx4]

veprx4, in my initial reply I actually suspected the headspacing, as it is critical with this round. However, I tryied to cover all the bases that could lead to the situation you were experiencing!

I go for 0.00" or flush to the chamber hood with my chambered rounds...

Part of the learning curve with the 9x25Dillon and the 357SIG rounds, good experience all around!

Agreed, but I had none of these issues reloading 357SIG. Go figure.

 

[veprx4]

veprx4,

I used a flat feeler gauge to measure headspace on my reloads. Set at a tight 0.002. With the naked eye you can barley see the relief of the shell base below the hood and with my thumb I can just feel a slight difference as I rub it over the hood and shell base. Hope this gives you an Idea of where it should be at.

I use an ISMI captured guide rod with the 22# spring and run a buffer technologies buffer. The rod works great. Occasionaly the allen head screw will work loose during a long range session of 10's and 9x25's even though I use lock tight. The buffer seems to help but I'm not sure it's needed with the plastic frame.

Sounds like you are on the way to solving your problem! Enjoy your 9x25!

Thank you sir. Hopefully I'll dial it in soon. Good idea about feeler gauge. I'll give that a try.

 

[veprx4]

You could tighten up the headspace by case sizing, but that really cuts your margin of error to a point of increased FTF/F possibility.

This shouldn't be an issue, with a Glock. Regardless of how/where the shoulder is spacing, the case head should space on the extractor, and the striker should find the primer, under any circumstance. I suspect either a short striker (worn out or modified), or a bad extractor (worn out or modified), or a worn/broken extractor spring/plunger. These are cheap parts, readily available. The case length allowance for the 10mm is .984-.992", significantly more than .002". Other cartridges fired from the same platform don't (regularly) see this issue, including .40S&W, which spaces solely on the extractor (when using the 10mm barrel, OEM or aftermarket), and especially .357Sig. If the problem were, in fact, the shoulder length spacing, we'd see this a LOT more with the other cartridges fired from the same platform.

Forcing the headspace by lengthening the shoulder may leave you with another issue, which is more of an issue, and can be dangerous. It won't take much residue to space the cartridge back far enough to prevent full battery lock-up, and may allow firing in the condition. This can also be caused by dirt, bullet lube, powder fouling, lead/copper particles, and even a dented/deformed case. As you are adjusting your shoulder length, keep a VERY close watch on the primer strike location. If any round appears to hit off-center, you've crossed that threshold.

Just a note for comparison:
In regards to pistol-fired shouldered cartridges, they set up and react very different from their rifle counterparts. I load and shoot .38-40 WCF, which is a shouldered (and rimmed) cartridge, fired from a Ruger BH, and lever action rifles. I have new .38-40 brass, but make most them from .44 Mag cases. New formed cases are not reliable, and must be fired once before they are (fire-forming). I size them long, so they will barely allow cylinder turning (zero headspace). Once fired, they will be perfectly headspaced to .004-.006", and allow for very easy rotation, and remain at that space, load after load. The same method is used for forming rifle brass, but a more typical post-firing headspace will be .001-.002", regardless of the cartridge caliber (although some require more than one firing).

dm1906, thanks for your excellent feedback. It's back to the range for another try tomorrow. If my headspace adjustments don't solve the issue, then I will start replacing parts.

 

[veprx4]

Success! Fired over 50 reloaded 9x25 Dillon rounds with no issues whatsoever. I used a metal straight edge and a piece of .003" shim stock to check the headspace adjustment before locking down the sizing die. Thanks to all for your helpful feedback. :cheers: