New brass issue.

[Denny Outdoors]

I bought 1000 Peterson 6dasher brass from the last run. If I load the new brass with any bullet jump I’ll get a couple of light primer strikes and will not go off. Jamming the bullets has zero issue. After I resize and load no issue. Any thoughts?

Rifle is impact action and proof prefit competition.

 

[AllenOne1]

They must have a lot of headspace at the shoulder and this is letting the case slide forward and causing a light strike.

Measure the base to shoulder length on a new case and compare that to a fired unsized case. I'm assuming you are going to see the case is stretching a good amount on that first shot.

 

[vaguru]

Neck the new brass up one caliber, then neck back down forming a false shoulder. When fired it will prevent case stretch and give perfectly fire formed brass in your chamber.

 

[iceng]

As @vaguru said. Use a 6.5mm expander mandrel, then size it back to 6mm, and you will get a real tiny shoulder "ripple", and that will form a new shoulder to fire from. Works a treat

 

[918v]

So jam. That’s the easiest solution.

 

[vaguru]

If you're worried about over working the brass expanding to 6.5mm and then back down to 6mm, you can accomplish the same by only going up to .25 caliber.