Dave Rabin
New member
Please help me diagnose a case failure: yesterday one of my .308 cases completely separated at the neck, just above the shoulder; the neck basically just sheared off and stuck in the chamber when the case was extracted. The cut was perfect -- it looks like someone used an extremely sharp saw and made a perfect cut straight through the neck.
Pertinent data:
1. The rifle is a stock .308 Win. Savage Model 12 Palma rifle. The cases are Lapua .308 Win. Palma cases that take small rifle primers.
2. I turned the necks on the cases, but just enough to clean up the high spots, taking off maybe .0005". I cut slightly into the neck/shoulder junction as I always do, no more and no less than all other cases I've turned.
3. I FL size each time but bump the shoulder no more than .002". I size the necks in 2 passes, first with a .337" bushing in the FL die and then with a .334" bushing in a neck sizing die.
4. The case had been fired about 9 times, always with either Varget or IMR 8208 XBR. I have never exceeded the published maximum charges. When this failure occurred, it was loaded with XBR, well below maximum.
5. I annealed the cases once, about two firings ago.
6. The bullets were the Sierra 155 Palmas.
If I'm doing something wrong I want to know it so I don't repeat it. If this is a metallurgical failure of some kind, is it serious enough that I should pitch that lot of brass?
Last thought: is there any way this could have been caused by the rifle? The cut was so perfect it just doesn't seem random enough to be a failure of the metal.
Thank you.
Dave Rabin
Pertinent data:
1. The rifle is a stock .308 Win. Savage Model 12 Palma rifle. The cases are Lapua .308 Win. Palma cases that take small rifle primers.
2. I turned the necks on the cases, but just enough to clean up the high spots, taking off maybe .0005". I cut slightly into the neck/shoulder junction as I always do, no more and no less than all other cases I've turned.
3. I FL size each time but bump the shoulder no more than .002". I size the necks in 2 passes, first with a .337" bushing in the FL die and then with a .334" bushing in a neck sizing die.
4. The case had been fired about 9 times, always with either Varget or IMR 8208 XBR. I have never exceeded the published maximum charges. When this failure occurred, it was loaded with XBR, well below maximum.
5. I annealed the cases once, about two firings ago.
6. The bullets were the Sierra 155 Palmas.
If I'm doing something wrong I want to know it so I don't repeat it. If this is a metallurgical failure of some kind, is it serious enough that I should pitch that lot of brass?
Last thought: is there any way this could have been caused by the rifle? The cut was so perfect it just doesn't seem random enough to be a failure of the metal.
Thank you.
Dave Rabin