Some questions and concerns have been raised about the possibility of the P320’s firing when out of battery, that is, when the slide isn’t fully forward. I recently had a chance to examine that issue when I tried to fire two different improperly-sized handloaded 40 S&W rounds in my pistol. (I won’t get into how that happened, other than to offer the warning to pay attention to what you’re loading in your magazines and guns and don’t make assumptions about your ammunition.)

The two cartridges showing incomplete resizing of the case heads.




This photo shows how far from chambering completely the one round sits in the barrel.




This round was even farther out.



The incomplete chambering kept the slide from moving fully forward, and when I attempted to fire, the pistol’s disconnector mechanism prevented a discharge. If they had fired, I suspect that a case rupture (kaboom!) would have occurred.

Although my gun is a statistical sample of only one, it functioned properly and prevented an out-of-battery discharge in two separate incidents.

Glad to hear and thanks for posting your results!

That is why I have taken to running all my .40 brass through a Redding RX-G die before loading

Good info and great pictures! I don't have the .40 version but it seems a person (low-volume shooter like me) might want to gauge their .40 rounds in the barrel before heading to the range - just as a precaution.

I don't have much defense ammo on-hand but I've been gauging defense rounds for years. Never ran into an oversized or overlength round - but I sure don't want to find out the hard way!

quote:

Originally posted by GeoJelly:
I don't have much defense ammo on-hand but I've been gauging defense rounds for years.

That’s something I definitely recommend. These are just some of the rounds in my demonstration box. The round on the left is another handload, but the others are factory, and the two 357 SIG cartridges are from a box of premium Winchester SXT.

Yeah, it happens. During a Basic Pistol class, one of my instructors called me over to the bench. He noticed something odd with a box of factory ammo. Two rounds sat lower than the others. Sure enough, bullets seated too deeply in the case.

I took them home, measured the OAL and contacted the factory. Sent the box back for their QC folks.

The bullets were 1/10" over seated. A full TENTH, not a few hundredths. Likely that something would have blown with those pressures. At least it was easy to spot...

 
I like, and use, the Ben Stoeger Case gauges. They gauge 100 rounds at a time, and when you are ready, flip them into a sacrificial Dillon case box, then flip them again into your regular Dillon box. It makes gauging cases a breeze, though they are a bit pricey at $100 each. It does speed up the process dramatically, if you insist on gauging every case.
 

quote:

Originally posted by sigfreund:
Some questions and concerns have been raised about the possibility of the P320’s firing when out of battery, that is, when the slide isn’t fully forward. I recently had a chance to examine that issue when I tried to fire two different improperly-sized handloaded 40 S&W rounds in my pistol. (I won’t get into how that happened, other than to offer the warning to pay attention to what you’re loading in your magazines and guns and don’t make assumptions about your ammunition.)

The two cartridges showing incomplete resizing of the case heads.




This photo shows how far from chambering completely the one round sits in the barrel.




This round was even farther out.



The incomplete chambering kept the slide from moving fully forward, and when I attempted to fire, the pistol’s disconnector mechanism prevented a discharge. If they had fired, I suspect that a case rupture (kaboom!) would have occurred.

Although my gun is a statistical sample of only one, it functioned properly and prevented an out-of-battery discharge in two separate incidents.

With the first 100 rds fired in my P320 the slide failed to go into battery 2 or 3 times. It was not out enough to notice until it failed to fire. I pushed it into full battery and it was fine. I have shot another 150 rds with no problems. As a side note the failures were with UMC ammo.

It's not just your pistol which would not feed ammo loaded or damaged like the photos Sigfreund. Most any pistol barrel would reject such deformed rounds. How they would fire out of battery is beyond my knowledge but, almost every round pictured above is easily diagnosed for its condition. The miss seated bullets, squatted .357 Sig cases, worked brass from not being aligned in the presses shell holder correctly.

I have assembled many a thousands of rounds on all manner of presses and have myself created some of these rounds. Some came from mixed, bulk brass I ordered by the mega pounds. It surely does pay to evaluate all your brass as you go.

The stickler in me never allowed me to run unprocessed brass through any of my presses. I took the time to process and clean all brass prior to running in my presses. That step at the bottom of a case would get rejected and bullet pulled.

The Lawman 9mm with the funky missing extractor groove I have never seen before. WTH is that?

quote:

Originally posted by David Lee:
The Lawman 9mm with the funky missing extractor groove I have never seen before. WTH is that?

That’s actually a Blazer aluminum 40 S&W round; I don’t remember the bullet weight.

Thanks, I cant keep those aluminum case rounds straight as I've never used them. It is a strange bird without the groove. Maybe a 180 grain.

Great topic. Many are confuzzled by it so it's a good one to review from time to time.

I remember a number of years ago on a different forum Glocks were being condemned for OOB firing because the slide could be withdrawn a certain amount and the striker still fell. It was the accepted line that Glocks are susceptible to OOB firing.

Naturally, this is ridiculous, and I provided demonstration of various other pistols that will do the same thing since the barrel and slide recoil a certain amount of distance before they unlock. The movement itself is not an indication of the potential for OOB firing.

A quick and easy test can be done to demonstrate the inability of a pistol to OOB firing.

Clear the pistol and inspect to make sure it is empty.

Rack slide to cock pistol.

Grasp slide and release, being careful to maintain hold on the slide and prevent it from flying forward.

VERY slowly lower the slide, all the while pulling the trigger.

Eventually, the spot can be seen where the striker/hammer will drop. It can also be seen that at that spot the barrel and slide are locked together.

It is a feature of all modern pistol designs to prevent OOB firing.

DO OOB firings occur?

Sure.

A high primer or debris on a primer or in front of the breech face or a firing pin jammed in the FP aperture all could cause the event.

quote:

Originally posted by lmacrichter:

With the first 100 rds fired in my P320 the slide failed to go into battery 2 or 3 times. It was not out enough to notice until it failed to fire. I pushed it into full battery and it was fine. I have shot another 150 rds with no problems. As a side note the failures were with UMC ammo.

WHY quote the complete OP's post with photos just to add this ^^^???

I'm just glad that it didn't fire out of battery and hurt you.

Thanks for sharing the pictures and info.

quote:

Originally posted by CD228:
I'm just glad that it didn't fire out of battery and hurt you.

There are far more gun safety rules than “the” four that people pontificate about, and this incident violated two of them: Don’t shoot other people’s handloads, and always pay attention to what you’re doing; don’t fall into mindless habits. What was worse, I did it twice even though the first time should have been, “Hey, dummy: Wake up!” Fortunately this was one more of countless examples of a hardware solution to a software failure.

The story is embarrassing to relate, but I hoped it would be of value in a discussion that sometimes comes up.

I pontificate about the "four" constantly. I've never went to the scene of a negligent shooting and walked up to the family, asked what happened, and was told "He was "accidentally" shot because he was eating on the range". And no eating/smoking/chewing tobacco is a safety rule.

It could happen, I guess.

Violating the safety rule about not ingesting lead through eating, using tobacco, or sticking fingers in one’s mouth won’t affect anyone except the person doing it—and even then not immediately—but it’s still part of my briefings. But then my briefings are much more thorough than most trainers’, and I’m sure that the people who’ve heard them 15 times could recite them as well as I can read them.

quote:

Originally posted by sigfreund:

quote:

Originally posted by CD228:
I'm just glad that it didn't fire out of battery and hurt you.

There are far more gun safety rules than “the” four that people pontificate about, and this incident violated two of them: Don’t shoot other people’s handloads, and always pay attention to what you’re doing; don’t fall into mindless habits. What was worse, I did it twice even though the first time should have been, “Hey, dummy: Wake up!” Fortunately this was one more of countless examples of a hardware solution to a software failure.

The story is embarrassing to relate, but I hoped it would be of value in a discussion that sometimes comes up.

Don't beat yourself up too badly.

I once fired a 9.3x57 round out of a 9.3x62. Never even noticed it till I ejected the round and marveled at the curious "Straight-Cased 9.3x62" hull I was holding in my hand...

That long Mauser extractor has its advantages.

quote:

Originally posted by sigfreund:
Violating the safety rule about not ingesting lead through eating, using tobacco, or sticking fingers in one’s mouth won’t affect anyone except the person doing it—and even then not immediately—but it’s still part of my briefings. But then my briefings are much more thorough than most trainers’, and I’m sure that the people who’ve heard them 15 times could recite them as well as I can read them.

Maybe if you eat enough ham sandwiches while shooting and reloading you can ingest enough lead to make ND's a real possibility...

https://www.youtube.com/watch?v=WVoxUgF7VbU

Wow. I have never seen that one before.