I have started to revisit seating depth/coal with an older 25-06. The rifle was originally purchased in 2000 so it has some age. I am getting concerned about throat erosion. Unfortunately, I didn't have equipment or knowledge I have now so I have no idea what it was 15 years ago.. Back then I used the old blacken the bullet and try it again and again to get it to shoot. I settled on 115 NBT as a good, accurate deer bullet. Today I measured the depth at which point the NBT touched the rifling.
115 Nosler BT - COAL at rifling = 3.325"
The Coal I had been using for years is 3.235" or 0.090" jump. The result is still pretty good, much less than 1 MOA. I am considering also checking other bullets. My results are;
117 Gr Hornady SPBT - COAL at rifling # 3.270"
117 Gr Sierra SPBT - COAL at rifling = 3.225"
What are suggested bullet jumps for the 3 bullets? The Hornady Is a Secant style Ogive. The Sierra is a Tangent style Ogive. The Nosler seems to be some kind of hybrid or VLD type Ogive.
115 Nosler BT - COAL at rifling = 3.325"
The Coal I had been using for years is 3.235" or 0.090" jump. The result is still pretty good, much less than 1 MOA. I am considering also checking other bullets. My results are;
117 Gr Hornady SPBT - COAL at rifling # 3.270"
117 Gr Sierra SPBT - COAL at rifling = 3.225"
What are suggested bullet jumps for the 3 bullets? The Hornady Is a Secant style Ogive. The Sierra is a Tangent style Ogive. The Nosler seems to be some kind of hybrid or VLD type Ogive.
