blow back

[new shooter]

what causes blow back on a case? Thanks for info.

 

[Pdvdh]

Need to be more descriptive.

From the case head area or at the shoulder/body junction?

 

[MudRunner2005]

There could be any number of problems that can cause excessive carbon blow-back on your brass. Most rifles will have some amount of blow-back on the case neck, and occasionally a little bit on the shoulder, that's normal.

Here is one of my 7mm RemMag brass that has been fire-formed to my rifle's chamber, cleaned, then neck-sized only, and shot again in the same rifle. This rifle has a custom match-spec chamber with a SAAMI neck measurement to avoid having to neck-turn your brass. This is considered a normal amount of blow-back...

Hope this helps.

 

[Pdvdh]

If the casing in that pic meets the definition of blowback, then blowback is a complete non-event.

 

[ltgibbson]

what area give us more information

 

[bpcrshooter]

did you anneal the brass?? Are you running high pressures?? what brass manufacture is it?? can you post a picture of it please??