Thread: What would have this felt like?

Originally Posted by 6x47

That's not just a simple case separation- the base of the case shows classic signs of big pressure. The primer has NO radius left and is pierced. There is a very clear ejector imprint as well. I DEF wouldn't have wanted to fire that round.

Case head separation can give those head stamp indications from a standard load. With the case separated there is no retention from the chamber wall friction and the detached end of the over sized case slams into the bolt face. Without any details of the load its imposable to say if it was over pressure or not.

He wouldnt have noticed anything. The case breaking like that reduced the pressures immediately. He might have noticed a little less recoil than normal....

I have had a couple of those over the years that look exactly the same, both were not noticable in any way until you open the action and the case drops apart into two pieces. Another one the case only let go most of the way around, and I didnt even notice till I got home.

Interestingly, in each case, the bullet still made part of a fairly normal looking group...

The lesson I learned was you can watch for the ring, a bit higher than you think - not the swipe mark from sizing - up from base of your old brass, and see when you need to junk the brass.
And a case head separation is not that big a deal.

As JohnDuxbury said, no big deal. Years ago I acquired a Parker Hale rifle in 308 off one of dads mates. Came with a heap of reloaded ammo. Had a 3 case head separations while I had that rifle and 2 with same ammo in another rifle. All Norma Re brass. No visible signs on loaded cases. Case head ejected and remaining case more or less fell out of chamber each time. Checked every fired case with sharpened split pin and culled dud cases ever since. That was back in early ‘80’s. Nick Harvey wrote an article about CHS around same time so was a problem easily fixed. Interesting learning experience. Recently culled some once fired PPU brass for same reason, that surprised me.

I had that happen 2-3 times now in .30-06 and .35 W. REM 700s in days past. Old over sized brass, warm loads, a puff of smoke through the magazine and a short case on ejection and the looking the give rifle a bit of a shake to get case remains out and brass brush to check all gone. No big calamity.


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A similar event which occurred near me on the range last year, with the same calibre.
Shooter not seriously harmed, aside from being very surprised and having a piece of the primer anvil pierce his skin on the forehead. The case body remained stuck in the chamber. Bolt was found in a roofing gutter up behind the firing line.

-BW- Doesn't look like normal case head separation there. Looks like it's blown at the extractor rim. Over pressure load ? Whatever, lucky shooter not to get seriously hurt.

Originally Posted by johnd

Looks like a typical case head seperation from ecxessive headspace and / or to much resizeing. Thats the one you can feel with a unfolded paper clip down the inside of the case.
If you look at the case wall you can see that its not a clean cut but goes up on a bevel as the case kept being reworked.
Just my opinion It could be totally wrong.

Dead right. Head separation from the case having the shoulder set back to far when sizing. Common with 6.6x55, 7x57 and likely others due to dies that are too short for the chamber. The heavily flattened primer is primarily due to a short case and not excess pressure.
GPM.

Greetings ,
A bit more detail. The headspace dimensions of some of the rifles and dies and chambers I have encountered may be of interest. Cases FL sized in recent Redding dies move the shoulder back 0.3mm (0.012") from fired position in my and a friends. For my M38 and a friends Ruger it is 0.45mm (0.018"). With an older set of Lyman dies it is even worse at 0.4mm (0.016") and 0.55mm (0.022"). Unfired Lapua cases are a good match for my Tikka. So the problem exists in the US. Somewhere along the line US die makers started using dimensions that were too short and this was only partly corrected when the 6.5 became a SAAMI cartridge.
This means that even with the tighter T3 chamber cases sized with the die hard down on the shell holder headspace will be grossly excessive, especially with older dies. When a cartridge is fired in these chambers the firing pin fall plus the primer igniting forces the case to the front of the chamber with the primer backed out hard against the bolt face. As pressure rises the case is forced back over the primer flattening it as shown in the photos. This happens even at some start loads.
Around 60 or so years ago Julian Hatcher wrote in American Rifleman that primer appearance was practically worthless for judging pressure. Others have repeated this over the years based on their experience. I am with them on this one.
Regards Grandpamac.

To belatedly answer the question posed in the OP, a case head separation is usually no big drama. The shooter is often unaware that there is a problem until they pull the bolt back and only part of the case comes with it. On the old Roy's Hill Range many years ago one of our detail was having head separation problems with his .243. Each time it occurred he whipped out a cleaning rod and ran a patch down from the muzzle and out popped the rest of the case. That sorted it was on to the next shot. Some banter was heard about his muzzle loading Manlicher.
GPM.

Originally Posted by woods223

-BW- Doesn't look like normal case head separation there. Looks like it's blown at the extractor rim. Over pressure load ? Whatever, lucky shooter not to get seriously hurt.

Correct, it wasn’t a case head separation as evidenced by the case head being visible in the photo. It was just ‘similar’ in being a case failure, and the resultant destruction of the rifle, which is a potential outcome of case head seperation.
Going on a tangent there, apologies

looks like it was close to a case of shooters head seperation from rest of his body.....pleased they werent decapitated.

Originally Posted by -BW-

Attachment 245614

A similar event which occurred near me on the range last year, with the same calibre.
Shooter not seriously harmed, aside from being very surprised and having a piece of the primer anvil pierce his skin on the forehead. The case body remained stuck in the chamber. Bolt was found in a roofing gutter up behind the firing line.

Greetings,
That is a catastrophic failure. Not only is the bolt missing but the top of the receiver ring and the bridge are gone. I see also that the front of the floorplate is blown off. Massive overpressure due to overload or barrel obstruction? It would be interesting to know if it had a scope fitted.
GPM.