Case Dimensions and Pressure ?'s


Well-Known Member
LRH Team Member
Aug 25, 2012
NW Minn
OK, Big time newbie question here.

When changing case dimensions and neck angle of a cartidge how drastically does that effect chamber pressures and velocity?
When using the same exact weight bullet and powder how much more velocity and chamber pressure will a .300 WSSM have than a .300 Win Mag
Or, let's say you have a straight walled cartridge like a .458 Win Mag. If you took that same weight bullet and same weight/type powder and turned the cartridge into a wildcat cartridge how much would that effect pressure and velocity?
A 5% increase in pressure and velocity?

How about the opposite. Take a 6mm PPC cartridge and use the same weight bullet and same weight/type powder in a straight walled case.
How much would the decrease pressure and velocity?

Or doesn't it effect velocity and chamber pressure that much by changing the dimensions of the powder case while using the same weight bullet and powder?

Thank you for your time.
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