Had a "boom" yesterday

[david walter]

Had a boom yesterday first round of some new reloads.

Known good rifle.

Blew the magazine out the bottom, blew the mag bottom off. Bolt hard stuck, case is still in there. See pictures.

223 rifle shooting reloads with 55 Hornady SP over 24.7 grains of TAC. Range brass (which might be the problem?), CCI 450s

Barrel does not seem bulged (as in obstruction), and it would be hard to fit too much TAC in a 223 case, especially under a 55 grain bullet.

Barreled upper is sitting at the 'smith's now waiting for him to have a look.

Thoughts on cause? Thoughts on breaking the rifle down to do forensics?

 

[acudaowner]

glad you weren't hurt or worse time to get a lottery ticket and a prayer of thanks .

 

[DocRDS]

do you load 300 BO?
Are you sure about your powder? (pull one and measure)
Measure your OAL

 

[hlee]

Inspect the case. Pull the bullets, dump the powder and inspect all of the range pick up brass. My general rule is “if it’s not good enough for the other guy to pick up, I’m not picking it up either…”

 

[nn8734]

Will know more about a cause when the stuck case is removed but possibilities include but not limited to:
1) excessive headspace
2) partial obstruction / object(s) in barrel near throat
3) overcharged case
4) wrong powder used
5) foreign object(s) in chamber

Gunsmith will tell you what happened and why; let us know what he says.

 

[david walter]

Could have been #1, 2 or 5.

we just checked the powder and it was right (pulled the other loads) on the rest of the batch which was loaded at the same time on the same machine.

OAL was set by the cannelure.

 

[TACC]

glad you are not hurt, interested in the findings

 

[gopherslayer]

Progressive press?

 

[david walter]

Dillon 550 RL. Well worn with a rebuild and upwards of 50,000 rounds on it.

it's a suspect, as well.

Progressive press?

 

[alamo5000]

My vote is for improperly sized brass.

I had a single incident before where it had the same net effect except my bcg split like a banana.

The bolt appeared "closed" but it was not fully in battery because of a single piece of brass.

 

[nn8734]

Dillon 550 RL. Well worn with a rebuild and upwards of 50,000 rounds on it.

it's a suspect, as well.

Possible but not likely unless youve had a pattern of issues across everything youve been loading on that press in the recent past.

6) Case structural defect

perhaps on the case web above the groove was excessively thin / partial separation signs not visible from the outside

 

[clcustom1911]

Coulda been range pickup that had unknown number of firings on it which could have contributed to a case head separation.

 

[TonyTheTiger]

I'm voting against case head separation. I've always got a handful of imminent separation rounds that slipped through initial brass QC, I shoot them all through a beater gun and it's pretty anticlimactic. Some extra noise and smoke out of the ejection port and then shaking the front half of the case out of the chamber when it cools.
I have kaboomed similar to the OP once. I was shooting in the crotch of a tree and bark was flying everywhere. I had a round not fully go into battery so I pulled the CH back a bit and it seemed to go all the way home. At the same time as I told myself not to shoot it, I pulled the trigger and blew the mag out, split the bottom of the carrier, blew out the extractor and locked the gun up solid. My best guess as to the cause was all the bits of bark in places it shouldn't be keeping it from properly going into battery.

 

[hlee]

I'm voting against case head separation. I've always got a handful of imminent separation rounds that slipped through initial brass QC, I shoot them all through a beater gun and it's pretty anticlimactic. Some extra noise and smoke out of the ejection port and then shaking the front half of the case out of the chamber when it cools.
I have kaboomed similar to the OP once. I was shooting in the crotch of a tree and bark was flying everywhere. I had a round not fully go into battery so I pulled the CH back a bit and it seemed to go all the way home. At the same time as I told myself not to shoot it, I pulled the trigger and blew the mag out, split the bottom of the carrier, blew out the extractor and locked the gun up solid. My best guess as to the cause was all the bits of bark in places it shouldn't be keeping it from properly going into battery.View attachment 7719500View attachment 7719501View attachment 7719499

But even then, if the gun was out of battery, the firing pin should not have been able to reach the primer...

And yeah, I have had a couple of partial separations in my Grendel- a bit of extra smoke and a "WTF I need to check my brass more closely" upon seeing the case. Still hit the targets under time...

 

[TonyTheTiger]

But even then, if the gun was out of battery, the firing pin should not have been able to reach the primer...

Yeah I know. It's a just a partial theory that I haven't spent a lot of time validating. It couldn't be an overcharge, the case is full of powder in that particular load and I couldn't seat a bullet if it had much more.

 

[alamo5000]

But even then, if the gun was out of battery, the firing pin should not have been able to reach the primer...

I had the exact same thing happen as Tony. The bolt was barely out of battery. Just enough to prevent full lock up. My carrier looked exactly like his.

 

[Missalot]

Are you absolutely sure you picked up the TAC bottle and not something else?

 

[david walter]

yes.

Are you absolutely sure you picked up the TAC bottle and not something else?

 

[david walter]

So, finally got the unit apart, and it was a case head separation. The upper, barrel and BCG are OK, the bolt needs replaced, and the charging handle is bent from me "mortaring" it to get the stuck case out.

No more reloads from pick up brass, I guess.

And no more reloads from friends.

 

[Huskydriver]

So, finally got the unit apart, and it was a case head separation. The upper, barrel and BCG are OK, the bolt needs replaced, and the charging handle is bent from me "mortaring" it to get the stuck case out.

No more reloads from pick up brass, I guess.

And no more reloads from friends.

Man glad you are good to go .. That's my biggest fear loading on 223 range brass

 

[david walter]

It was "exciting" to say the least.

I don't recommend it to the faint of heart. I probably have 40,000 to 50,000 rounds out of ARs and M4s in my life, and this was the first major failure.

I feel lucky it didn't cause any damage to me.

 

[srt-4_uk]

I had the exact same thing happen as Tony. The bolt was barely out of battery. Just enough to prevent full lock up. My carrier looked exactly like his.

That's not how it works though. Even if the carrier is slightly back, the bolt is still headspaced and lugs are, at the very least, partially engaged. Even before the lugs are no longer engaged, the firing pin won't reach the primer. Assuming the primer isnt seated high, which is a reloading issue.

Sure it's hard to overcharge because of powder choice but bullet setback will spike pressure just as easily.

 

[supercorndogs]

That case head was blown off by excessive pressure. ITs not the cause of the pressure, but the result. A normal CHS, is not going to blow a chunk out of the case head, or expand the primer pocket like that.

 

[MtnCreek]

Was the press being used to load a different cartridge prior to these 223 being loaded?

 

[david walter]

Dillon 550C, and the whole tool head was switched, including a dedicated 223 powder funnel, he said.

I’m with you guys. Looks like a reloading error.

I have everything I need to roll my own now.

 

[MontanaMan]

I’m with you guys. Looks like a reloading error.

I agree & yes, unless the chosen powder fills the case completely, it really is possible to get enough extra of the really fine grained or ball powders into the case to make that happen.

MM

 

[TonyTheTiger]

That case head was blown off by excessive pressure. ITs not the cause of the pressure, but the result. A normal CHS, is not going to blow a chunk out of the case head, or expand the primer pocket like that.

Agreed. A normal CHS due to worn out brass is pretty boring. Just had one Monday, didn't even know it till I picked up brass and found the two halves.

 

[supercorndogs]

I had one once where the bolt didn't close because it ran the next round up inside separated case. I laughed when I saw what I extracted, then searched and found the case head. It looked like a 9mm case on the ground. I shot the rest of that ammo through my bolt action. A few more of them separated.

 

[TonyTheTiger]

I had one once where the bolt didn't close because it ran the next round up inside separated case. I laughed when I saw what I extracted, then searched and found the case head. It looked like a 9mm case on the ground. I shot the rest of that ammo through my bolt action. A few more of them separated.

Been there. I once tried small rifle magnum primers in 9mm and it gave constant separations in blowback guns. All the live rounds I extracted had a cute little hat, they looked like rimless .38 Special cases.

 

[SWgeezer]

this separation is due to a gross overload, I have pieces of an upper that I did that on, the case looks exactly the same, mine actually ruined the upper housing, the bolt, the bolt carrier, and the magazine. It was caused by a powder substitution. I have also separated a barrel extension on my 243 wssm. Mine was through my Dillon 550 25-30 years ago. Still have the pieces as a reminder.

 

[rustyinbend]

I handload precision ammo in 6.5-CM, 300-WM, 300-PRC, and 338-LM for skills development and LR-to-ELR competitions. My AR's I've always just shot for fun using the cheapest factory ammo I could find. I've been thinking about starting to reload 223 and 300-BLK ... but this thread just changed my mind.

 

[TonyTheTiger]

I handload precision ammo in 6.5-CM, 300-WM, 300-PRC, and 338-LM for skills development and LR-to-ELR competitions. My AR's I've always just shot for fun using the cheapest factory ammo I could find. I've been thinking about starting to reload 223 and 300-BLK ... but this thread just changed my mind.

Why? None of the mistakes in this thread are caliber specific, they could happen no matter what you load for.

 

[rustyinbend]

Why? None of the mistakes in this thread are caliber specific, they could happen no matter what you load for.

I was being a bit "tongue-in-cheek" ... it's more for me about "volume reloading" vs. "precision handloading". Any decision to load mag-fed 223 or 300-BO means a commitment to "not" checking every round for sizing, seating, charge, concentricity, and the other 14 things I do to look at each round to ensure the best possible precision and consistency. Plus ... the whole "pick up someone else's range ammo" thing just seem crazy to me. It seems a little like taking off on a cross-country trip in a 1972 Yugo with 325,000 miles on it and with $100 in your pocket and no credit cards ... based upon the guy that sold it to you for $300 telling you it was in perfect working order.

 

[SilencedShooter11B]

If I pick up range brass and I can tell it’s probably been reloaded (ie crimp removed, case mouth chamfered, the other usual suspects), I toss it in the recycle bucket. I tend to stick with LC, PSD, FGMM and others due to the characteristics that lend to them being once fired: Primer crimp, primer sealant, annealing plainly visible not fading away, that type of thing

It may only be on 2-3 firings but I generally find enough 1x that I don’t need to keep everything I find. I’ve probably filled 3-4 gallon ziplocs with 1x Lake City brass this year and I’ve been limited on my range time due to work lately

Glad you are safe and have all fingers and eyes, OP

 

[TonyTheTiger]

I was being a bit "tongue-in-cheek" ... it's more for me about "volume reloading" vs. "precision handloading". Any decision to load mag-fed 223 or 300-BO means a commitment to "not" checking every round for sizing, seating, charge, concentricity, and the other 14 things I do to look at each round to ensure the best possible precision and consistency. Plus ... the whole "pick up someone else's range ammo" thing just seem crazy to me. It seems a little like taking off on a cross-country trip in a 1972 Yugo with 325,000 miles on it and with $100 in your pocket and no credit cards ... based upon the guy that sold it to you for $300 telling you it was in perfect working order.

That's fair. You could buy once fired military brass and avoid most of these problems. LC is good stuff, relatively cheap and you'll know how many firings are on it.

 

[isofahunter]

I witnessed almost the identical experience, post shot review of the reloading procedure turned out to be the use of a pistol primer not SRP. PP can cause a first and secondary ignition in rifle cases based on what we determined First unlocks the bolt, second creates a mess.

 

[srt-4_uk]

I witnessed almost the identical experience, post shot review of the reloading procedure turned out to be the use of a pistol primer not SRP. PP can cause a first and secondary ignition in rifle cases based on what we determined First unlocks the bolt, second creates a mess.

So the first ignition sent the bullet down the barrel and had enough gas to start to cycle the action. Then the remaining powder in the barrel ignited to blow up the upper even though pressure could freely travel out the front of the barrel?

Or was it basically a squib that stopped just past the gast port then detonated?

 

[david walter]

Went to the range today and shot 50 rounds through this upper and barrel with only a new bolt, once it was put back together.

Ran fine.

 

[david walter]

Well, there is that.