Aguila kaboom

[Stev0]

Dedicated AR22 upper, CMMG barrel & bolt.
It was more of a loud poof than a kaboom. The rear of the case blew out of the chambered round & the heat ignited the top round in the mag (I think it was heat unless somebody has a better idea). The indent in the mag round looks like it was pressed against the feed ramp of the collar. The bullet in the pic must be from the mag round; I found it on the bench after I pulled the upper off.

The mag looked something like this when I pulled it out. The shredded case was angled forward more & there were about 15 more rounds in it. The front of the left feed lip broke off, there's a small crack at the left rear that extends about 1/2" from the top, & the halves separated at the top rear.

The next round in the mag.

The offending ammo.

The only damage to the gun was a broken extractor spring. Replaced the spring & fired about 35 rds of the same lot number without issue. Two days later the rear of another case blew out (7th round of the day). Broke another extractor spring. I don't think I'll be firing anymore rounds from this lot again. On the day of the first kaboom/poof I fired between 160 to 165 rds without issue. 200 rounds prior to that without issue. So 2 rear of case blowouts out of about 400 of the same lot. Previously I've put about 1,000 rounds of 2 different lots of Super Extra through this rifle without issue.

2 questions
Did heat cause the round in the mag to fire? Anyone else have problems with Aguila?

 

[deltawiskey]

I had a dedicated 22lr CMMG upper that fired when the bolt wasn't completely closed and the case exploded.
DW

 

[obx22]

Only Aguila issues I’ve had were with the Super Maximum. Ammo goes from stopping in the barrel, to nearly blowing out the extractors, absolute worst extreme spread I’ve ever seen.
I’ve had other brands blow rims in a dirty autoloader, always attributed to fire out of battery (bolt bounce).

 

[fpgt72]

I had a dedicated 22lr CMMG upper that fired when the bolt wasn't completely closed and the case exploded.
DW

That is what I would think as well, sounds like out of battery. 22 rimfire there is not all that much pressure. I would think some kind of impact to the nose of the round in the mag likely "set it off". If that bullet was from the one in the mag it looks like the nose of it could have taken a hit. That might explain the big dent in the one under it in the mag.

I agree I would shy away from the ammo "just in case" but I think there could be other things at play here. When shooting that rifle I would really watch it next time, for roughly 200 rounds. Now if you totally tore down the rifle, and are replacing the mag you could remove the issue, and we may never know.

I am firm in the camp of if it is made by man it can be screwed up. I have had screwed up factory ammo before. One 45acp case with no primer and powder all over the box. Buddy had a squib with factory ammo. Lucky for him the gun would not go into battery, the bullet just in the barrel, we had a talk on watching for impacts after that, as well as if anything feels "funny" full stop.

 

[justin amateur]

It's rimfire.
Brass can be weakened and crack during case forming.
Can't see it, but fire the cartridge and it will get your attention.
Overcharged cartridge will completely separate the head and fragment the brass.
Out of battery will deform and rupture the case above the rim.
It's not if it will happen, it's when, especially with bulk cartridges.
I've had magnum rimfire cartridges blow the bottom out of my 455 three times.
CCI paid for repairs each time and replaced the ammo.
Winchester, Remington, Aguila, Armscor, Cascade International,
Sellier&Bellot, Browning have all given me 22lr case ruptures.
Shoot a lot of rimfire, it'll happen to everyone.

By bulk cartridges, I mean those not made in Europe.
Doesn't matter if it's packed in a 50 cartridge box,
when you can see obvious indications of rough handling on the assembly line.

 

[fpgt72]

It's rimfire.
Brass can be weakened and crack during case forming.
Can't see it, but fire the cartridge and it will get your attention.
Overcharged cartridge will completely separate the head and fragment the brass.
Out of battery will deform and rupture the case above the rim.
It's not if it will happen, it's when, especially with bulk cartridges.
I've had magnum rimfire cartridges blow the bottom out of my 455 three times.
CCI paid for repairs each time and replaced the ammo.
Winchester, Remington, Aguila, Armscor, Cascade International,
Sellier&Bellot, Browning have all given me 22lr case ruptures.
Shoot a lot of rimfire, it'll happen to everyone.

By bulk cartridges, I mean those not made in Europe.
Doesn't matter if it's packed in a 50 cartridge box,
when you can see obvious indications of rough handling on the assembly line.

Odd I have never had it happen, and I shoot a fair amount of rimfire. I have come across "hot" ones, and ones that did not leave the barrel. I have yet to come across a 22mag have an issue. Personally I think the lower volume tends to give you a tick better quality.

I really enjoy 22mag, I just wish it was not so darn expensive, and hard to find.

I have for years said well I should just get a 17, but always come back and say, why My 22's do everything I need them to do. However I can say hitting a starling with a 17 is a bit of a giggle factor.

 

[justin amateur]

Magnum rimfire is hunting/varminting ammo.
Doesn't get used like cheap bulk 22lr.
A few shots per morning, not like plinking ammo.
You can make a magnum brick last for year's.

When you do finally catch a bad cartridge, remember this conversation.

 

[Stev0]

That is what I would think as well, sounds like out of battery. 22 rimfire there is not all that much pressure. I would think some kind of impact to the nose of the round in the mag likely "set it off". If that bullet was from the one in the mag it looks like the nose of it could have taken a hit. That might explain the big dent in the one under it in the mag.

I agree I would shy away from the ammo "just in case" but I think there could be other things at play here. When shooting that rifle I would really watch it next time, for roughly 200 rounds. Now if you totally tore down the rifle, and are replacing the mag you could remove the issue, and we may never know.

I am firm in the camp of if it is made by man it can be screwed up. I have had screwed up factory ammo before. One 45acp case with no primer and powder all over the box. Buddy had a squib with factory ammo. Lucky for him the gun would not go into battery, the bullet just in the barrel, we had a talk on watching for impacts after that, as well as if anything feels "funny" full stop.

That's similar to the first thought I had. The round didn't chamber because of the brass already there causing the rear of the case to dip back into the mag & the bolt impacting the side of the case igniting it. I don't know if that's possible but would explain the feed ramp indent. I know I only pulled the trigger once FWIW.

 

[tomme boy]

22rf is one cartridge I have not had any real problems with. At least a ruptured case. I have shot over 100,000 rounds easily over my lifetime so far. Leading, yes. Duds, YES. Squibs, yes. But never a rupture.

I have 4K rounds of the Aguila 22 40gr coming tomorrow. It is one of my favorite budget rounds. That round above was fired out of battery.

 

[MarinePMI]

It's rimfire.
Brass can be weakened and crack during case forming.
Can't see it, but fire the cartridge and it will get your attention.
Overcharged cartridge will completely separate the head and fragment the brass.
Out of battery will deform and rupture the case above the rim.
It's not if it will happen, it's when, especially with bulk cartridges.
I've had magnum rimfire cartridges blow the bottom out of my 455 three times.
CCI paid for repairs each time and replaced the ammo.
Winchester, Remington, Aguila, Armscor, Cascade International,
Sellier&Bellot, Browning have all given me 22lr case ruptures.
Shoot a lot of rimfire, it'll happen to everyone.

By bulk cartridges, I mean those not made in Europe.
Doesn't matter if it's packed in a 50 cartridge box,
when you can see obvious indications of rough handling on the assembly line.

This ^^^^

@Stev0 I agree as well that it was likely an out-of-battery ignition. Probably blew the case head back and down onto the top of the magazine, rupturing the top round and igniting the powder. As the powder ignited, and bullet came out of the neck, the bolt got blown back, shredding the case mouth (just a guess on that last part).

Regardless, that clean separation of the case head, goes to what @justin amateur was alluding to. It would appear that those cases weren't properly annealed after case rim forming. It's been quite a few years since I consulted for Aguila (new management now), but I would send them pictures along with the lot number ([email protected]). They've had a few incidents (as all manufacturers do) where some bad ammo slipped past QC, but historically, have made things right when they thought it might have been their ammo (you'd be surprised how many people claim bad ammo blew up their gun, when it clearly wasn't). You can download their complaint/claim form here:

https://content.aguilaammo.com/uploads/Aguila_Ammunition_Customer_Complaint_Form_a3bf24951b.pdf

 

[Stev0]

I assume you guys are saying the bolt was out of battery on the case with the head separation since the other one obviously was. I guess it's possible but it looks like the rim took a pretty deep hit from the firing pin. I don't know. I'll try different ammo tomorrow.

Thanks for the links MarinePMI. I'll contact them when I have a better grasp on what happened. I have around 600 rounds of that lot left, maybe I'll try it in a different gun. Although I probably should contact them before I do that.

 

[6.5SH]

Good slow-mo video of how much the bolt bounces without weights and high velocity ammo:

 

[Stev0]

Thanks for the vid 6.5SH. I guess bolt bounce could've been an issue if the bolt didn't go fully into battery after bouncing. I should've mentioned in my first post I was firing slowly, probably at least 5 seconds between trigger pulls.