Ppc case blow back

[Sleepyhollow]

For the life of me I can't find the cause. First I thought I was too thin on my necks being 81-82 on a .262 neck. So I turn some new brass to measure. 260.5 on the bullet ring. Fire formed nice wave around necks. 2 firing blow back plum to the case head on some.

 

[liljoe]

How much powder?
Joe

 

[Sleepyhollow]

How much powder?
Joe

30.0 n133

 

[DDT414]

Did you anneal?
I sometimes anneal after fire forming and my sign wave goes away but will come back after another firing or 2

 

[X Count]

Too much bullet jump or too much shoulder bump? Had something similar with another cal

 

[Ccrider]

^^^ How much are you bumping the shoulder back?

 

[gunsandgunsmithing]

Something doesn't add up here. Never seen it like yours and a stiff appropriate powder charge, so I'd guess it's related to annealing but I don't know. Is that a dent in the shoulder..case on right. Supports low pressure.