jenstapio
FNG
Hey Roksliders,
Alright I have a 300 Norma improved and run Lapua brass, N570 and 230 Bergers through it. 92.4 grains at around 3096-3100 for final loads and 70 grains N570 with 230s to fire form
I’m curious what other 300 NMI users are doing for their fire form process?
I had one of my pieces of brass show some head separation signs at 4 firings so I started paying closer attention to my brass. I noticed more of my brass showing early signs so I thought maybe I was sizing my shoulders back too much and causing excess pressure. I double checked everything and confirmed I was only sizing back .002 from chamber length. I even started to notice a faint line at the case head/web area after the first fire form through my gun. I have been running 70 grains of N570 with a 230 to fire form it out as my gunsmith who built the gun recommended the lowest powder charge for a standard 300 Norma load to fire form.
I’m stumped as to why I’m getting signs of separation so early? Do I need to go even lower on my powder charge with the 230’s to fireform? How low do you guys go? Or is the Lapua brass just not holding up?
Any input is appreciated!
Thanks
Below is a picture of the brass one fire bottom, two fires in the middle and the top pic is 4 firings.
Alright I have a 300 Norma improved and run Lapua brass, N570 and 230 Bergers through it. 92.4 grains at around 3096-3100 for final loads and 70 grains N570 with 230s to fire form
I’m curious what other 300 NMI users are doing for their fire form process?
I had one of my pieces of brass show some head separation signs at 4 firings so I started paying closer attention to my brass. I noticed more of my brass showing early signs so I thought maybe I was sizing my shoulders back too much and causing excess pressure. I double checked everything and confirmed I was only sizing back .002 from chamber length. I even started to notice a faint line at the case head/web area after the first fire form through my gun. I have been running 70 grains of N570 with a 230 to fire form it out as my gunsmith who built the gun recommended the lowest powder charge for a standard 300 Norma load to fire form.
I’m stumped as to why I’m getting signs of separation so early? Do I need to go even lower on my powder charge with the 230’s to fireform? How low do you guys go? Or is the Lapua brass just not holding up?
Any input is appreciated!
Thanks
Below is a picture of the brass one fire bottom, two fires in the middle and the top pic is 4 firings.