7mm Hornady A-tips

[SmokinCrow]

Huh. Interesting. I can push 199 Hammer Hunters in my .300 norma improved at 3300 with absolutely no pressure signs. And burning around 91 grains of N-570. I guess with your increased powder charges and smaller projectile I'd have expected these to fly quite a bit faster based on a .300 norma case. How did they "pattern" on the target?

I believe I've always heard that the larger diameter and bearing surface allows for a greater pressure to build up increasing velocity. That's why a .308 will push a 160 grain bullet around the same velocity a 260 will push a 143 grain bullet. I always thought that the smaller lighter bullet be faster.

 

[25WSM]

It's actually the other way around. The bigger the bore the less pressure. Think of the 30-06 pushing a 150 grain bullet at 3000 fps but a 270 with a 150 will only do 2900. They are all using about the same amount of pressure its how big a hole can you force it through. The bigger the hole the easier it is to push it out with same weight projectile.
Shep

 

[Ed AO]

N570 will give faster speed in the 7 but torches the throat rapidly.
The 300 RBH on the other hand will push the 230 berger @ 3160 with N570.
N570 in the 7 bore is not one I'll use.
Yes this is from experience

I have no doubt of your experience but mine is different with n570. I have fed my 28nosler n570 it's whole life and I have over 600 rounds through it. I only shoot 3 at a time though and letting it cool down. Still shoots one hole and still shoots great at distance. RBROS rifle by the way. That's just my experience.