Mystery dent...?

[itchyTF]

What about a kernel of unburnt powder in the chamber? Looks about that size.

 

[NorCalMikie]

"Pressure getting past the neck may put a dent in that area, if using starting loads of the slowest burn rate powders. Dent not seen in a 308 yet? Happens with large magnums and is not common. Produces extra soot. A longer than normal OAL can add to the problem, letting the bullet move sooner than normal."

Should blow out the next time it's fired.

 

[FreQRiDeR888]

I was getting dents like that from not using enough powder in my 300 winmag loads. Being the first time loading magnum rifle loads, I started with too conservative a load. If theres not enough innitial preasure the brass won't seal the chamber, causing blowback. Are you near or below recommended starting load? Is it all the same brass? Case capacities can vary quite a bit!

 

[scott_at_vortex]

If the dents are identical and in the same exact spot then it was absolutely caused by some kind of debris in the chamber. Like some one mentioned already it could of very likely been a kernel of powder. I have had that happen a number of times. The kernel will generally dissipate after 3 or 4 rds in my experience .

Come to think of it I just had this happen this past weekend. I could probably dig through my brass and find the pieces it happened to.

 

[RemingtonAI]

The load is under the max for what is safe in my rifle but I believe is the stated max load in the hornady manual. No excess carbon or anything. All the same brass on the same cycle. Only thing different about this range day was that it was raining. Don't think anyone commented on my question as to whether it could have been a drop a water on the case? We'll see on saturday. Should be nice in the morning to see if the rent appears, and by noon there should be thunderstorms so I'll be shooting in the same conditions and will be inspecting my cases as I go. I'll be sure to post results

 

[waldo1979]

+2

+3

 

[waldo1979]

i've seen dints like that where someone soft seated and then dumped a cartridge in their chamber. Little bits of extruded powder can get stuck in there and are really hard to get out.

 

[sfldiver]

+3

+4

Had the same problem last night while resizing some brass. I received a new container of Lyman spray lube yesterday from MidwayUSA. I lubed the cases a bit heavy with the spray lube, and my cases started coming out with the dent under the neck. Once I backed off on the lube, no more dents.

Heavy lubing definitely causes denting.

Adrian