Failure at the range today.

[boltfluter]

Consider yourself very lucky in this instance. Even more caution is warranted, when using heavy for caliber bullets, in such a small case as the .223. Carry on, cautiously, young man.
Paul

 

[Dr. Matt]

Are those adjacent fired rounds in your ammo box loaded the same as the compromised piece? Please clarify, 23.5gr varget was the powder charge? They certainly don’t look over pressured if so. The case failure certainly looks like an over pressure event. Excuse me if I’m misinterpreting or didn’t read it somewhere in your post.

In the post I stated that I reduced the charge to 23.5. That was incorrect. I reduced it to 23.8. They are all loaded the same yes. The only thing different about all 100 was the neck tension. I know better than to change something and not work up to the final charge. No excuses....

 

[EEP]

In the post I stated that I reduced the charge to 23.5. That was incorrect. I reduced it to 23.8. They are all loaded the same yes. The only thing different about all 100 was the neck tension. I know better than to change something and not work up to the final charge. No excuses....

That one round doing that and the others didn’t…. don’t sound like 23.8gr nor neck tension is your root cause to me. There has to be a better explanation.

 

[Dr. Matt]

In a .223, going .5gr over max is a LOT! Looks to me like you're way over pressure.

It'd be really helpful to know chrono numbers, but I guess you didn't do that?

Yes the first 8 were 2650-2695fps at the muzzle. I didn't look at the down range numbers yet. The failure was 2345 fps

 

[Dr. Matt]

That one round doing that and the others didn’t…. don’t sound like 23.8hr nor neck tension is your root cause to me. There has to be a better explanation.

These are the first 8.

 

[Murray Brook]

@EEP
Certainly agree with you. Something doesn't add up especially with the failure at 2345 ft/sec

 

[Straightshooter1]

Yes the first 8 were 2650-2695fps at the muzzle. I didn't look at the down range numbers yet. The failure was 2345 fps

Yup, that 2650 - 2695 is really high for a 16.5" barrel. The decrease to 2345 seem right for a case failing like that (loosing pressure).

 

[chop house]

In a .223, going .5gr over max is a LOT

Yup

 

[Dr. Matt]

That one round doing that and the others didn’t…. don’t sound like 23.8gr nor neck tension is your root cause to me. There has to be a better expla

Yup, that 2650 - 2695 is really high for a 16.5" barrel. The decrease to 2345 seem right for a case failing like that (loosing pressure).

20 inch barrel , but still a dumb mistake. I unloaded the remaining rounds and made notes about what I did in the log book.

 

[Bill K]

Well you pushed it too far when you change to another addition in your load and your rifles chamber. Pressure shot way over and you made a bomb, instead of a safe load. You were fortunate it was not worse.

Admittedly, I have been pushing it a little.

 

[Dr. Matt]

After sleeping on it, these are my thoughts.
I made a series of mistakes. The first was trying to make a 5.56/223 Wylde chamber shoot like a 308. I put safety on the back burner and focused on down range performance. I didn't see any pressure signs- until I did. But why?
The load work up for with Lupoa brass worked well for hundreds of rounds. The brass was on its 5th reload. I changed a component with out working up the load properly and went straight to neck tension and seating depth. This was a mistake, no excuses.
I "got away" with it until the phone rang. I was at my back yard range and had a 5 minute conversation while the round sat in a hot chamber. This removed any ( if there was any) safety margin left. I don't have my phone with me at the public range so this has not happened before. Now I need to go back and rethink the Lupoa loads just in case one of them gets a hot soak.
"Never exceed max load" means never exceed the max f'in load. Thanks for the comments. Lesson(s) learned.

 

[BigBolt]

I had an incident at the range today and would like opinions about what happened and what to do differently from here on out.
I shoot a Unitah 223/5.56 Wylde chamber upper on a standard AR lower. Night force optic. About 1500 rounds down range on this set up. I have been shooting Lupoa match brass, CCI No.41 primers, 24.0 grains of Varget, 90 grain Hornady A-tip.
Last month I shot 2 MOA at 1000 yards at the Dead Zone shooting Park. All was good.
Because the Lupoa brass is hard to find, I bought a lot of new Nozzler brass. I reduced the charge by half a grain and though I would work up a load with this new brass. The ninth shot was exciting. View attachment 1575941 was exciting. I'll post pictures. View attachment 1575932View attachment 1575935View attachment 1575938

 

[243winxb]

Lupoa match brass, CCI No.41 primers, 24.0 grains of Varget, 90 grain Hornady A-tip. *I bought a lot of new Nozzler brass.*

Running a maximum + loading found a defective case.

Case volume & bullet bearing surface has a direct effect on pressure.
Proof loads average 73,500 PSI.





It could have been worse.

If primer pockets become loose in 5 firing, or less, the loading is over pressure. Too Hot.

 

[EEP]

After sleeping on it, these are my thoughts.
I made a series of mistakes. The first was trying to make a 5.56/223 Wylde chamber shoot like a 308. I put safety on the back burner and focused on down range performance. I didn't see any pressure signs- until I did. But why?
The load work up for with Lupoa brass worked well for hundreds of rounds. The brass was on its 5th reload. I changed a component with out working up the load properly and went straight to neck tension and seating depth. This was a mistake, no excuses.
I "got away" with it until the phone rang. I was at my back yard range and had a 5 minute conversation while the round sat in a hot chamber. This removed any ( if there was any) safety margin left. I don't have my phone with me at the public range so this has not happened before. Now I need to go back and rethink the Lupoa loads just in case one of them gets a hot soak.
"Never exceed max load" means never exceed the max f'in load. Thanks for the comments. Lesson(s) learned.

“Hot Soak + Hot Load” = That makes sense! Thanks for sharing! This may help someone else out down the road.

 

[nakneker]

You certainly could have used more caution Dr Matt but the good news is, you, yourself didn’t get hurt and a lesson was learned. It’s hard to come on here and admit a mistake, adapt your methods and move onward.

 

[SeabeeKen]

Did you have to seat shorter OAL due to the Wylde chamber? If so, was it shorter than the OAL Hornady used? That could send pressures quite high. You and the guys shooting next to you were lucky. Perhaps a different cartridge will suit your downrange needs.

 

[Dr. Matt]

Did you have to seat shorter OAL due to the Wylde chamber? If so, was it shorter than the OAL Hornady used? That could send pressures quite high. You and the guys shooting next to you were lucky. Perhaps a different cartridge will suit your downrange needs.

No, the opposite. The base to give were 2.052. that's .035 off jam. Very much longer than factory

 

[243winxb]

Wylde chamber

https://www.accurateshooter.com/cartridge-guides/223rem/

See- 223 Remington vs. 5.56×45–Chambering and Throat Considerations

the Wylde chamber, that feature longer throats.

 

[Dr. Matt]

You certainly could have used more caution Dr Matt but the good news is, you, yourself didn’t get hurt and a lesson was learned. It’s hard to come on here and admit a mistake, adapt your methods your methods and onward.

I really thought I would a lot harsher criticism. Thanks for the thoughts and kind words. Lessons learned and shared.

 

[Dr. Matt]

Running a maximum + loading found a defective case.

Case volume & bullet bearing surface has a direct effect on pressure.
Proof loads average 73,500 PSI.

View attachment 1576035

View attachment 1576034

It could have been worse.

If primer pockets become loose in 5 firing, or less, the loading is over pressure. Too Hot.

Yup, lost sleep over this.