What conditions led to this?

[DGP4]

I saw something similar when a guy at the range shot 30-30 ammo out of an old Enfield in 303 British.

 

[DShortt]

Looks like the wrong ammo for whatever the rifle was chambered for. Either that or maybe someone used the wrong sizing die?

Hard to guess without more specifics.

 

[JSH]

Maybe a gas gun set up wrong?
I see crap like this off and on, and it seems more regularly now.
I usually don’t even try to guess, as it might be catching.

 

[Shooter13]

Happen to notice any blood spots or twisted. metal pieces laying around?

Or fingers?

 

[bobm]

Closer up of the symbol and compared to .308

 

[rockhound78]

Yep, looks like 6.5 Creedmoor shot in a magnum chamber of some type

 

[Steve Blair]

Sellier and Bellot headstamp.

 

[Shooter13]

Similar to but not Alpha mark
View attachment 1421194

Agree, not the same.

 

[DGP4]

Here's a clearer pic of the head stamp

Sellier & Bellot - Wikipedia

en.wikipedia.org

 

[ckaberna]

The big question is how did the target look?

Lol, just kidding. This day and age this really doesn’t surprise me.

 

[ronsatspokane]

Fired in the wrong chamber. Something that was perhaps 6.5 but a bit larger diameter through the body.

 

[X Count]

Short mag makes some sense. 6.5 creed and 6.5 PRC are interchangeable aren't they? . . .. just like 223 and 556?!

 

[spencerhenry]

If they were fired in a larger chamber, why are the necks / shoulders not blown out?

 

[varmintshooter]

I think that you can get 1 more load out of those.

 

[LHSmith]

How about waayyy over-annealed -like down to the case head to the point the back end could not take pressure without rupture?

 

[Eagle Six]

Never thought very good about S&B metallic or shells. The last experience was a guy at the range with a expensive factory 6.5 Creedmoor with a Vortex scope (not bad) he was sighting in for his daughter. S&B was printing a 4" group at a 100 yards! I offered 3 rounds of Norma Golden Target (not great, but it usually will print MOA. Watching him he was doing everything right and I thought may the scope was doing some crazy stuff. Three shots inside a 1/2". Gun and scope were fine. His ammo not so much.

Why do you think it was factory loaded? The shooter above did mention the S&B had a bit more recoil than the Norma. I looked at a few of his cases and nothing out of the ordinary. So was it hot factory loads, hot reloads, wrong chamber? What's the mouth inside ID?

 

[Kurz]

The symbol you're discussing is pertinent to S&B brass. It represents 'Neroxin' which is a priming compound. The symbol can appear as a single element, double element or even a triple element in few situations.

 

[chop house]

Any pics of the shoulder and neck ?

the brass or the shooter?

(groan... sorry)

 

[Jeff Porter]

Flaming bomb arsenal mark on SB not an alpha

Edit to add.

It appears after a short google search it represents the priming component neroxin. Like Kleenbore

Arrow on the circle.

 

[Dave M.]

This morning there were 30-40 of these left on the firing line. (slobs) Not a one was without a head crack or splitting. Looks like it was new factory ammo.

Seems fairly obvious that these may have been fired in the wrong chamber.