Blew Primer out on a starter load...

[MMH]

Was developing some loads for my 300 BLK & blew a primer out and this was on a starter load (17.8 gr. of AA1680 under a 155 gr. BTHP). Gun functioned. Noticed blown primer when I pulled brass out of the catcher. Case is carboned up on the back face but otherwise looks OK. I am guessing a loose primer pocket? The rest of the loads shot fine. Not to say I could have not made a mistake on that cartridge, but I fairly careful and weigh all charges.

Comments?

 

[6.5SH]

Is a good reason to pay attention to the feel when seating primers. Something that felt abnormally easy or hard to seat needs to be set aside and examined.

 

[Lawnboi]

First shot? Solvent in the bore or chamber?

 

[918v]

Neck too thick?

 

[MMH]

Don't know. As I said, I'm fairly careful in my reloading. If primer is easy or tight, I inspect. Obviously I missed something. Do not believe that it was a dangerous situation, but still a little concerned.

 

[roostercogburn98]

COAL?

 

[hafejd30]

Brand primers?

Winchester?

 

[MMH]

COAL?

2.200 COAL. 1.635 to ogive. Chamber is 1.675, so 0.040 of jump - no 'jam' seating.

Primers were Federal 205.

 

[Baron23]

Just sounds like a loose pocket, no?

 

[mtrmn]

Seat another primer and find out.