Bassnbow
Well-Known Member
I have a relatively new Tikka 7 PRC rifle with a 22" Proof barrel with 110 rounds through it while fire forming brass. I just started load development and am testing Berger 175 Elite Hunter bullets. I contacted Berger for load data and they sent their data sheet for that bullet. Finally got out this morning to shoot my first ladder test using H1000. My brass is once fired Petterson and I'm using Federal Match Mag primers. The Load data Berger sent me was for a 26" barrel and their MAX load listed was 70.6 grains which produced 2973 max velocity. I purposely kept my max load at 69.8 grains and my ladder was done with .3 increments. At 68.9 grains I went over their max listed velocity and mine was 2989 with no signs of pressure. At 69.2 I was at 3003 and still no sign of pressure. 69.5 was 2996 and 69.8 was 3003, but both had very slight pressure signs with a slight bolt lift and very slight shiny spot on base.
I know I'm at pressure with their listed velocity and the signs I'm seeing, but I'm not sure if the pressure will increase or decrease with the brass now that it has been fired twice and likely fully formed. When I sized the once fired brass I purposely did not bump the shoulder back because I knew it was not fully formed yet. I used a #10 Redding Competition shell holder and it didn't move the shoulder at all. Fortunately I did locate a couple of promising nodes to explore in the mid 2850 range, but very curious about what would occur with the brass now that fully formed, will it speed up or slow down?
I do have two other strings to run, one with RL26 and the other H4831sc, so not sure if I might run into early pressure there also? Obviously very surprised with velocity with the 22" barrel. Please advise on your thoughts
I know I'm at pressure with their listed velocity and the signs I'm seeing, but I'm not sure if the pressure will increase or decrease with the brass now that it has been fired twice and likely fully formed. When I sized the once fired brass I purposely did not bump the shoulder back because I knew it was not fully formed yet. I used a #10 Redding Competition shell holder and it didn't move the shoulder at all. Fortunately I did locate a couple of promising nodes to explore in the mid 2850 range, but very curious about what would occur with the brass now that fully formed, will it speed up or slow down?
I do have two other strings to run, one with RL26 and the other H4831sc, so not sure if I might run into early pressure there also? Obviously very surprised with velocity with the 22" barrel. Please advise on your thoughts