Diagnosing an almost squib round

[gk3]

I've been reloading for a little over 2 years. I keep a spreadsheet, which shows 10,500 rounds loaded, mostly pistol. I've never had anything close to a squib, but I just upgraded from a Lee Classic Turret to a Dillon XL650, and had an issue with the first batch.

I loaded 300 rounds on the Dillon and took them to the range yesterday. I shot all 300, and all ran fine except two rounds. The first was a primer that failed to ignite, happens seldom (CCI 500). The second failure was an extremely low recoiling round that failed to eject and spilled powder all inside the gun. The projectile managed to hit the target, but it was so weak that I did inspect the barrel before continuing. I recovered the case and it was not split and the primer was still seated properly.

I use Dillon 9mm dies, and might not yet have them perfectly adjusted since I am learning a new machine. I also use the Dillon powder check die.

Gun is a G17. Loads are 147gr Bayou with 3.3gr HP-38 and 1.14 COL. Chrono data attached. I shoot USPSA Production and am just above power factor.

I'm trying to figure out what happened with that round since it's a new reloading machine and I've never experienced this kind of failure before. I have some theories, but maybe someone here has been there before.

 

[Walkalong]

Failure to fire, assuming no gun issue, and I do, is almost always a primer not seated firmly enough (Getting used to a new priming system maybe?)

Can only guess about the weak round that spilled powder. No neck tension?

 

[kidneyboy]

What Walkalong said ^^^^
My guess is no neck tension. Recheck your dies.

The most inconsistent part of a fully functioning Dillon press is the operator.

 

[PhillySoldier]

The spilled powder sounds like it may not have been seated/crimped properly

 

[Blue68f100]

That or you may have short stroked the machine. Which may have caused the powder dispenser to not fully dump. Fail to fire in most cases is the primer not being fully seated if it fired on the second attempt. The powder check die should have picked up on it.

 

[gk3]

The crimping die was my main concern. I think I need to add a little more crimp to account for variations in brass. I was thinking the projectile ended up loose in the cartridge after being chambered.

 

[mcb]

I don't believe the lack of crimp/neck-tension alone would have left un-burnt powder in a 9mm. There would have been enough resistance at the throat to cause a powder as fast as Hp-38 to burn nearly normally.

Sound like wet or contaminated power IMHO. Since it only happened on that one round I would guess there was moisture from a wet tumbling process, excess case lube or possible even some dry tumbling media caught in the flash hole in that one specific cartridge. The fact the bullet left the barrel means at least some of the propellant burned (primer alone rarely can push a bullet out of a barrel) but you found un-burnt powder inside the gun so clearly not all of it burned. Sound most like some of that one cartridge's powder charge was contaminated buy a liquid if I was going to guess.

 

[gk3]

mcb, thanks, I hadn't considered that. I dry tumble with walnut media, but I have used Nufinish in the media in the past. I also recently tried a light coating of case lube, but I don't think it was necessary or excessive. Perhaps the case had a waxy clump of media in the bottom.

 

[Toprudder]

Could be a very slim chance, but with new dies, it is possible that there was still some oil on the dies from the factory. Oil can contaminate the powder. Clean the dies, powder funnel, etc. just to make sure.

Nothing against them, but Lee dies are the worst, IMHO, for being covered in oil when new.

 

[Texas10mm]

Since you're new to the Dillon there are a few upgrades I would recommend to you.

1. Primer shutoff switch
2. Quick remove powder measure gadget

Are you running a powder check of any kind? When I run one I use a RCBS lock-out die.

 

[Walkalong]

The crimping die was my main concern. I think I need to add a little more crimp to account for variations in brass. I was thinking the projectile ended up loose in the cartridge after being chambered.

Neck tension holds the bullet. Check the sizer with the thinnest brass and see if it sizes it down enough.

 

[thomas15]

Neck tension holds the bullet. Check the sizer with the thinnest brass and see if it sizes it down enough.

I'm going with this as the likely problem. Assuming that the problem is un-burnt powder without enough neck tension the bullet could simply fall out of the case after feeding into the chamber. That would explain almost all of the conditions you report but I think you were lucky for a number of reasons. Since you are a semi-volume reloader it is hard to get personal with every single round you handload but a quick check for high primers and split case walls before storage is a good practice. If, when you place the bullet on the case mouth is feels lose then take that one out, don't expect the taper crimp to hold it, as mentioned it is case mouth tension.

 

[mdi]

Spilled powder but bullet hit the target? Sumpin' sounds off. A primer alone may drive a bullet out of the barrel, but hit the target without burning powder doesn't sound right. Two out of 300 ain't too bad and that number will prolly go down as you get used to your Dillon. I would agree the two were more than likely from ill seated primers...

 

[DudeRick]

I had to come back and reread his statement too. Spilled, unburned powder left in the barrel after the projectile has exited makes no sense. If it spilled down into the gun, it had to have spilled out as the cartridge was being stripped off of the magazine which means the projectile was just setting in the case with no neck tension. Sounds like somehow you missed both the sizing and the crimp die with this round.

 

[Englishmn]

I have had some cases I wet cleaned didn't let dry long enough and loaded pfft pop lot of powder was left. Also had some duds that when pulled had wet primers.

 

[snakeye]

I agree with Walkalong....the 9mm case is a tapered case and relies on neck tension on the bullet bearing surface...you should only crimp just enough to take the flare out of the case. If the neck tension is not correct pressure will not build up in the case to effect a proper burn....I have had cases that when you resize them, the ram on my LCT will slam down with no resistance whatsoever...these cases have lot their workability and don't /won't resize and go straight to the recycle tub. Of course I can feel this on my LCT but I imagine it would be hard to feel this on a progressive press...since this was only 1 round out of 300 I wouldn't imagine it would be a systemic issue, more of a single occurrence for whatever reason, but maybe test checking several single cases on the press and running each single case through the sizing die might be in order.

 

[gk3]

Something else that I forgot to mention during the setup of the dies -- I think I had too much bell on the case. I was adjusting flaring after scraping the coating off a few times during bullet seating. I was also seating the bullet with the round nose side of the seating stem, but I later realized that the 147 Bayou FPs work better on the other side of the stem. I'm wondering if the projectiles were tilting as they were entering the seating die when making contact with the round nose side of the stem, and as a result scraping, which caused me to add more flare than necessary to prevent scraping. Even with the added flare, I still occasionally scraped a few. It's possible that something didn't size back properly or that I skipped or short-stroked something during this troubleshooting.

I do have a rough QA process that would have noticed any egregiously bad rounds, and I do put the rounds into MTM cases (primer side up) to look for primer issues, but I agree with all the comments on neck tension. I ordered some of these to improve my QA process.

When the bad round fired, the mouth of the case locked the slide open and was jammed into the front of the ejection port, and that's how powder spilled inside the gun, and some onto my hand.

I appreciate everyone's input. I have learned something.

 

[SamT1]

Is it possible the bullet was undersized. I don’t think a 32 bullet would stay in at all and don’t believe there is anything in between. Maybe someone has an idea on this front.

I have a hard time thinking the crimp could do that to that degree. Was the case covered in black suit?

I don’t think lube would do it.

Water could, but not likely with dry tumble.

How sensitive is the powder cop die or whatever your using. Will it alert a 1/2 charge?

Powder can bridge up in a new powder die that’s oily, been there done that. You could have dumped the bridged oily powder all in
one case.
I noticed some 45’s I was loading didn’t look as full, weighed a change and it was 3.2gr of 5.0 I went on and loaded 5 before cleaning it with a qtip and alcohol. I decided to shoot em and see what happened. They shot like that, barely cycled the gun. You could almost count to 2 before it would lock.

 

[Walkalong]

Spilled, unburned powder left in the barrel after the projectile has exited makes no sense. If it spilled down into the gun,

It doesn't take all that much to get a bullet out of the barrel and to a close target.I am guessing it is unburned more than spilled powder

 

[Toprudder]

With some lightly loaded 9mm, using Power Pistol in a 16" AR, I had an occasional shot that did not sound right. I opened the gun so I could look down the barrel, and inside the barrel was some unburned powder, not just a few flakes, but what looked to be about 1/4 of the total charge. Happened several times. The bullet always made it out, though. When I upped the charge, the problem went away. I chalked it up to not enough pressure for a complete burn. Funny thing, though, is that I used that same load in my pistols without a problem.

 

[Walkalong]

Interesting. The pistols stay locked for a split second compared to the blowback AR.

 

[DukeConnor]

How are you cleaning your brass? Wet or dry ?

 

[gk3]

How are you cleaning your brass? Wet or dry ?

Dry with walnut. But, I had a friend get out of reloading and I bought all his supplies, so I ended up with a big lot of 9mm brass (likely from a brass reseller) that looks wet tumbled because of how clean the insides of the cases are, but I'm almost back to loading my own tumbled brass. I was using Nufinish and mineral spirits in the walnut media, but I might be over that now.

 

[buck460XVR]

I don't believe the lack of crimp/neck-tension alone would have left un-burnt powder in a 9mm.

Same here, even with mixed brass of varying thickness. Its a pistol, if the case chambered, odds are there was enough crimp. Fast burning powders used in 9mm do not need the heavy crimp like with magnum revolvers and slow burning powders. I suspect technique with a new progressive press is the most likely scenario. The addition of a primer failure along with the almost squib round also gives one to wonder.

 

[243winxb]

The primer’s extra gas unseated the bullet while still trying to light off the main charge,

Read more: http://www.shootingtimes.com/ammo/ammunition_st_mamotaip_200909/#ixzz5S7fU35kX

Neck tension keeps bullets from moving to soon.

Magnum primes help ball powder start burning better. Even more so at starting loads. (3.3gr HP-38 )

Increase neck tension with a Lee U carbide undersize die. Check expander diameter.