Kaboom 💥 Today 😟

[Culpeper]

It was no longer .

I just got a 100, 1x fired .243 Lapua brass. Would my primary health care provider be annoyed if I asked her to have them X-rayed?

It was no longer Lapua 308 Win brass. No point with going to Lapua claiming bad brass. It was Ginger 708AI brass. I think he narrowed it down to the problem that lead to this.

 

[Mike Matteson]

I've had case head separation with 280AI with Nosler Sammi brass fired in Original Ackley Improved chamber just as you speak of.

I have never had the case rim destroyed that way though.
Now, I always use the paper clip tool to check when I see the ring develop on any case...especially after several firings.

Me too! I pay very close attention to my cases and primers. All case are subject to separations. I use belted mag rifle over the years a lot. I would lose case in 3 firing due to case separations. Changed to neck sizing only and stop that. Would lose cases from primer pocket in about 12 firing after that. My powder loads are over what any reloading manual ever shows. So that was the reason for that.
Part of my problem is I can't ref to any of my reloading manuals except for one. I have manuals from the late 50's to present. I update about every two years or any new additions. I don't throw them out either.
I have had case separation from to many firing, and wasn't watching for problems. That was a great many years ago. I don't now. Sometime you can teach an old fart new trick. Hard to brake them of old habbits.

 

[Allen Kitts]

I'm still having a hard time accepting that me pushing shoulders back .001-.003 too far on the fire forming loads on 1X fired brass would cause a case rupture. Heck 300WM cases stretch the shoulders .018" upon initial firing.

I always seek to find fault in myself. As you have read thus far. There is however the notion I didn't screw up. This kind of thing drive a guy mad! LOL

Ok now that I am over the holy **** phase after seeing that pic. It looks more like a major case failure to me as well. I have no where near the experience as most of the guys on here when it comes to the technical side of reloading but I have been doing it for more years than I care to admit and in my opinion, this is catastrophic failure not just case separation. Something went seriously wrong and I don't think a neck setback of a couple thousands would have caused this type of failure. The line of break is almost perfectly symetrical all the way around. Maybe during the sizing process that piecs of brass was just stretched to thin at that point and could not handle the pressure and separated. The part I don't understand is the blow back through the case head.

**** man that's scary.

 

[DoneNOut]

So, sized 308 Win to 708 and accuracy was good for 200 rounds. Then after fireforming you had accuracy issues?

Daggum great! This is 708 mode:

708AI mode: No neck clearance

H100V and RL 17 same junk

Yesterday W760 was showing promise with touching groups. H100V still junk. RL17 two shots touching.

The velocity on kaboom round was 2100fps. This makes me wonder. Case fell right out, not smashed into the chamber. Case mouth and shoulder on ruptured case look fine. Dimensions of brass is good.

 

[Allen Kitts]

The 708 was shooting pretty darn good, why the change?

 

[Mike Matteson]

I have to go along with GL Taylor and ButterBean. Never seen anything like that. I am glad I haven't either.
Wonder if he taken other cases apart to check on powder loads? I do a inspection on my cases after loading powder into them before I place bullet in them.
i have gotten to moving my powder cases to another tray each time. That way I don't miss any or try and double load them. I have done that a few times in days gone by.

 

[Wachsmann]

Also 100V when shooting in my 6.5X284 Norma seem to spike some when over 80 degrees and really spiked when 90 degrees. I had to drop about 1/2 grain for summer time shooting.

 

[DoneNOut]

This was 46gr RL17

 

[DoneNOut]

The 708 was shooting pretty darn good, why the change?

Because it has a 708AI chamber

 

[Roughrice]

Very high pressure made the case head disappear.

Was it a donut, plus bullet jammed into rifling?

Or the low neck tension allowed the bullet to move out of the case to soon. This may cause a 2nd pressure spike. It acts like a plugged barrel.

I thought of this as well.
Perhaps a bullet out of spec?
Maybe .285+ od causing plugged barrel affect and pressure had to release somewhere quicker than the bullet could exit.

 

[Culpeper]

Daggum great! This is 708 mode:
View attachment 486001
708AI mode: No neck clearance
View attachment 486002
H100V and RL 17 same junk

Yesterday W760 was showing promise with touching groups. H100V still junk. RL17 two shots touching.

The velocity on kaboom round was 2100fps. This makes me wonder. Case fell right out, not smashed into the chamber. Case mouth and shoulder on ruptured case look fine. Dimensions of brass is good.

I think you narrowed it down to the cause as far as process timeline. You're just going to have to check several things. Glad to see you are okay, which is the most important thing here. Then comes the why.

 

[DoneNOut]

I have to go along with GL Taylor and ButterBean. Never seen anything like that. I am glad I haven't either.
Wonder if he taken other cases apart to check on powder loads? I do a inspection on my cases after loading powder into them before I place bullet in them.
i have gotten to moving my powder cases to another tray each time. That way I don't miss any or try and double load them. I have done that a few times in days gone by.

I charge each case individually with a 1500 Chargemaster. There's no hidden double charge. If I load the same case twice, there's 46gr of powder spilling everywhere.

 

[DoneNOut]

I thought of this as well.
Perhaps a bullet out of spec?
Maybe .285+ od causing plugged barrel affect and pressure had to release somewhere quicker than the bullet could exit.

I just finished my neck turning session and checked the OD of the necks with loaded rounds. .309 all of them with no variation detectable.

 

[ButterBean]

I'm still having a hard time accepting that me pushing shoulders back .001-.003 too far on the fire forming loads on 1X fired brass would cause a case rupture. Heck 300WM cases stretch the shoulders .018" upon initial firing.

I always seek to find fault in myself. As you have read thus far. There is however the notion I didn't screw up. This kind of thing drive a guy mad! LOL

I concur