9mm ammo slug pushed down into cartridge.

[Thethickster]

I was loading up my G17 9mm clips with some Speer Lawman 124 gr. ammo and noticed the slug was pushed down a tad like the round had falled on its nose and got pushed in somehow. Side by side to the other Lawman ammo they are shorter. I was just wondering if this ammo is safe to shoot or should it be discarded. Thanks.

 

[JDGray]

Do not fire the setback round! Was it rechambered a few times?

 

[Thethickster]

I believe so it was 2 rounds out of the 25 or so I had of the Speer Lawman I had. Im guessing it was the first round out of the clip. Since I sometimes go outside and do foot patrols with it locked and loaded.

 

[herrwalther]

Sounds like bullet setback alright. Either pull it or soak the primer to make it inert but DO NOT FIRE IT. Try to avoid clearing and rechambering a round more than you have to. This causes undue stress on the bullet and pushes it farther down the case. Some firearms and ammo companies are more resistant to bullet setback. Such as Blazer SPP .45 looks like a midget 9mm when it is setback.

 

[beatledog7]

In case nobody else gets around to saying so, Glocks use magazines, not clips. I don't usually make this point, but everybody needs to educate someone at some time about something.

 

[MedWheeler]

Definitely become knowledgeable on "bullet setback." Essentially, it occurs frequently when a specific cartridge is re-chambered more than a couple of times. Each time it's chambered, the tip of the projectile strikes the feed ramp, and repeated such impacts can drive the bullet further back into the case. This decreases the space inside the case in which the powder burns, which in turn increases case-wall pressure when the round is fired. The result can be a violently-bursting case, which has great potential for causing damage to the firearm and injury to the shooter.

Most of us here agree that a round chambered more than two or three times should be relieved of "carry duty" and expended at the range during practice (unless it's already been noticeably shortened, in which case it should be rendered inert.)

 

[Thethickster]

Thanks Beatledog and Madwheeler for the info. Just seemed kinda of odd ive always used Winchester 9mm Nato's and have never seen this problem. I got about 100 rounds of 115gr Winchester white box is this common with this ammo also?

 

[Jim K]

Just for curiosity, has anyone PERSONALLY experienced a blowup that they KNEW was due to bullet setback and KNEW had no other cause, like bore obstruction or overload?

I have read time and again about the dangers of set-back, but it always seems to be a third or fourth hand story, or "I saw on the net" kind of thing. I once ran some experiments with several ammo brands and various degrees of bullet set-back and couldn't get anything bad to happen.

So I would like to hear FIRST HAND of a Ka-boom caused by set-back that was investigated and definitely shown to be from that cause only. Please, no links, no "third cousin" stories, no "reports", no references to someone else. Personal experience only.

Jim

 

[tarosean]

is this common with this ammo also?

Its common for any type of ammo that you continually chamber and unload. If you want to practice racking, chambering, etc. Get you some snap caps.

 

[herrwalther]

Just for curiosity, has anyone PERSONALLY experienced a blowup that they KNEW was due to bullet setback and KNEW had no other cause, like bore obstruction or overload?

No. But why risk it? Even at their current "panic" level, ammo is still cheaper than replacing your firearm, hand, or eyes. If I can eye see or caliper measure setback, probably not going to keep it in my firearm.

 

[ku4hx]

That's known as cartridge set back and in high intensity rounds has a tendency to raise pressure substantially.

Do you suspect it to be a factory condition? If not and you set the bullet back by repeatedly chambering that round, you need to alter your protocols.

 

[JDGray]

Just for curiosity, has anyone PERSONALLY experienced a blowup that they KNEW was due to bullet setback and KNEW had no other cause, like bore obstruction or overload?

I have read time and again about the dangers of set-back, but it always seems to be a third or fourth hand story, or "I saw on the net" kind of thing. I once ran some experiments with several ammo brands and various degrees of bullet set-back and couldn't get anything bad to happen.

So I would like to hear FIRST HAND of a Ka-boom caused by set-back that was investigated and definitely shown to be from that cause only. Please, no links, no "third cousin" stories, no "reports", no references to someone else. Personal experience only.

Jim

You are in a sense, creating an overload with a set back. With limited case capacity already, a 9mm does not need much setback to become overpressured. I've seen a few case ruptures in a G17, shooting factory reloads... After the second one, I told the guy to stop shooting next to me, and we looked at his ammo to find some of them setback. Yes, they could have been overcharged, but most 9mm powders will overflow the case if it were double charged, so it would have needed to been over filled by not double charging... Kinda unlikely if you ask me. The guy was lucky to leave with just a blackened finger, no gun damage, or worse, body damage.

 

[ku4hx]

Just for curiosity, has anyone PERSONALLY experienced a blowup that they KNEW was due to bullet setback and KNEW had no other cause, like bore obstruction or overload?

I have read time and again about the dangers of set-back, but it always seems to be a third or fourth hand story, or "I saw on the net" kind of thing. I once ran some experiments with several ammo brands and various degrees of bullet set-back and couldn't get anything bad to happen.

So I would like to hear FIRST HAND of a Ka-boom caused by set-back that was investigated and definitely shown to be from that cause only. Please, no links, no "third cousin" stories, no "reports", no references to someone else. Personal experience only.

Jim

Huh? If we did this for all the old wives' tales, fish stories, gun lore, internet wisdom, gun rag expert positions, "I heard", "I read", "I was told" and the like, there'd be a serious lack of "stuff" to talk about.

 

[zeke4351]

First of all you need to quit playing with your gun and racking shells in and out of it. Why are you doing it? Second thing is the only setback test I have seen is a guy seating bullets too deep on purpose to prove it makes no difference. Drive the bullet down in the casing as far as it will go and it still shoots fine. The shorter shell might fail to feed in your gun but I doubt it. There is too much BS on most gun sites that is not true.

 

[zeke4351]

You are in a sense, creating an overload with a set back. With limited case capacity already, a 9mm does not need much setback to become overpressured. I've seen a few case ruptures in a G17, shooting factory reloads... After the second one, I told the guy to stop shooting next to me, and we looked at his ammo to find some of them setback. Yes, they could have been overcharged, but most 9mm powders will overflow the case if it were double charged, so it would have needed to been over filled by not double charging... Kinda unlikely if you ask me. The guy was lucky to leave with just a blackened finger, no gun damage, or worse, body damage.

The pressure is the same no matter where the bullet is seated. I have seen a lot of Glocks that have case bulges so bad you can't reload them. It's a Glock thing, not set back.

 

[Schwing]

The pressure is absolutely effected by the bullet depth. If you are loading light loads, you will probably get away with seating them deeper... Try that with heavy loads and you WILL have a problem. case.

 

[coolluke01]

Since I sometimes go outside and do foot patrols with it locked and loaded.

I know this isn't your question, but I feel it needs to be addressed.

Unless you are employed by your State, city or county and patrol is in your job description, DON'T DO IT! Don't go looking for trouble, because you may just find it. It's not your job and needs to be left to those who are employed for that purpose. Your handgun is for your own protection, don't be a Batman or Rambo.

I don't mean to be too hard on you, but this is a very important thing and I just want to make sure you have the right thinking.

Just to provide some credibility.
NRA Instructor, NRA Basic Pistol and State of MN Certified Permit to Carry Instructor.

 

[Lj1941]

Over-Pressure

I have had an overpressure situation with a handload in a 9MM Taurus PT 111 PRo that was most likely caused by bullet set-back.Although I did not have a blow-up it damaged the slide and made it necessary to send the weapon to Taurus. They repaired the gun at no cost to me except the cost of overnight air VIA UPS.It made me more careful when loading and unloading any pistol.LESSON LEARNED.:banghead:

 

[MrCleanOK]

I was also a little curious about the "foot patrol" thing. I have done a few, but only in other countries. If you're just walking around the neighborhood or property, that's called "going for a walk".

 

[herrwalther]

The pressure is the same no matter where the bullet is seated. I have seen a lot of Glocks that have case bulges so bad you can't reload them. It's a Glock thing, not set back.

Do you even know what pressure is? Pressure is force per unit area applied in a direction perpendicular to the surface of an object. Push down an object and it increases pressure. Do that on top of gun powder and you have the makings of a problem. Fill a gallon jug of water up a third and try to squeeze it. Easy. Won't spill unless you puncture the jug. Now do it with a full one, make sure you have a towel ready. Not quiet the same as a bullet on top of gun powder but the same pressure principle.

 

[1KPerDay]

The pressure is the same no matter where the bullet is seated.

ummmm....

 

[Jim K]

It seems the answer to my question is "No". A lot of maybes and "heard abouts" and problems but no definite proof or even real investigation of those so-called "set-back" blow ups. It seems to just be assumed that any handgun blow up is caused by bullet set-back and no one bothers to question that or check for any other possible cause.

In my experiments I found that it was about impossible to duplicate some of the reports. One report of a 9mm that had been chambered repeatedly supposedly had the bullet nose barely showing above the mouth of the case. I could not duplicate that condition because the powder would not allow the bullet to seat that deep and if it did the case bulged so badly it would not chamber. (Cases are not perfectly cylindrical internally; they are thicker toward the back, limiting bullet set-back even when the bullet is forced deeper in a loading press or a vise.) I believe the story was fiction.

Does seating the bullet deeper cause high pressure? IMHO, if so, not enough to cause concern. Seating bullets deep has often been done in rifles where the bullet is long and the magazine short. I do not recall hearing of any blown up rifles caused by deep seating the bullet, even crushing the powder.

Jim

 

[JDGray]

Temp fate if you want, but deep seating anything will raise pressure. A rifle bullet is designed to fit in the mag, or should I say, designed to meet SAMMI specs for the cartridge at max OAL. Unless your using the wrong bullet for the application, you shouldn't need to seat it deeper than the reloading data, to fit in a magazine. Why do you think manuals list a min seating depth? It is perfectly safe to compress rifle loadings, too.... As long as the book says so.

 

[zeke4351]

The pressure is absolutely effected by the bullet depth. If you are loading light loads, you will probably get away with seating them deeper... Try that with heavy loads and you WILL have a problem. case.

Tell me where you found your information so I can be educated.

 

[1KPerDay]

Here's one place... http://www.frfrogspad.com/miscelld.htm#components

A special warning! Seating depth, especially in small capacity high pressure cases, like the 9 mm and .40 S&W, has a major effect on pressure. Tests have shown a 20 - 25 percent change in pressures with as little as .05" in seating depth in these cartridges. A chart for the .40 S&W changing seating depth with the same charge and brand of cases is shown below. If you couple a change from a thin case to a thicker case with less volume and a change in seating depth it become clear that you can get in big trouble very fast. This is especially true if you are using cases that have been reloaded a lot and a pistol that has poor case head support.

Change in seating depth
(inches) Pressure
(psi)
0 35,000
-.05 41,500
-.1 48,900
SAAMI specification for the .40 S&W are

Max Average Pressure - 35,000 psi
Maximum Probable Lot Mean - 36,100 psi
Maximum Sample Mean - 37,800 psi
Minimum Proof - 45, 5000 psi
Maximum Proof - 49,000 psi