This one has me scratching my head...
I acquired a 300NM last winter, ordered a box of Lapua brass and a batch 230 Bergers. This thing shoots nearly one hole at a hundred with 96.5gr of R50, no pressure signs. Shot a group at 325 that measured just over .750” with the new brass. I am tickled pink.
Now fast fwd to once fired brass, same load and I get obvious pressure and 2”+ groups at a hundred. Back too new brass, one hole again and no pressure.
Once fired trimmed to same length, also tried .010 under, shoulders bumped back to no resistance on chambering. Full length sized with no expander then opened back to .002” neck tension.
I’ve been reloading for 50yrs and not run into this one before. Looking for somebody smarter than me to explain what the hell is happening. Thanks
I acquired a 300NM last winter, ordered a box of Lapua brass and a batch 230 Bergers. This thing shoots nearly one hole at a hundred with 96.5gr of R50, no pressure signs. Shot a group at 325 that measured just over .750” with the new brass. I am tickled pink.
Now fast fwd to once fired brass, same load and I get obvious pressure and 2”+ groups at a hundred. Back too new brass, one hole again and no pressure.
Once fired trimmed to same length, also tried .010 under, shoulders bumped back to no resistance on chambering. Full length sized with no expander then opened back to .002” neck tension.
I’ve been reloading for 50yrs and not run into this one before. Looking for somebody smarter than me to explain what the hell is happening. Thanks