08-22-2012, 10:06 AM
Von,
I don't personally believe the CCi 450 is absolutely necessary in the Grendel cartridge its self.
What I have witnessed in the primer testing I have done, is that the (non-magnum) Rem 6 1/2 and the CCi 400s may provide higher velocities in compressed charges i.e. (31g CFE223 under 130g Norma @ 2.265" OAL) and give lower ES and SD. My best guess for this is, with a compressed charge of powder, the lighter detonation of a non-mag primer ignites less powder at the instant the primer detonates, providing more powder burn time as the projectile moves down the bore toward the muzzle, basically the burn rate is more linear to the rate of projectile travel.
I can't say that all powders will behave this way, but I have data showing that CFE223 does.
CCi recommends the use of their magnum primers for Ball Powders
The Rem 6 1/2 has a thin soft cup and regardless of the powder charge (when used in loads for the Grendel) will exhibit cratering, Which; I now believe to be splash from the firing pin strike.
The recommendation for a harder thick cup primer in an auto loading rifle is more in the lines of safety rather than performance.
I don't personally believe the CCi 450 is absolutely necessary in the Grendel cartridge its self.
What I have witnessed in the primer testing I have done, is that the (non-magnum) Rem 6 1/2 and the CCi 400s may provide higher velocities in compressed charges i.e. (31g CFE223 under 130g Norma @ 2.265" OAL) and give lower ES and SD. My best guess for this is, with a compressed charge of powder, the lighter detonation of a non-mag primer ignites less powder at the instant the primer detonates, providing more powder burn time as the projectile moves down the bore toward the muzzle, basically the burn rate is more linear to the rate of projectile travel.
I can't say that all powders will behave this way, but I have data showing that CFE223 does.
CCi recommends the use of their magnum primers for Ball Powders
The Rem 6 1/2 has a thin soft cup and regardless of the powder charge (when used in loads for the Grendel) will exhibit cratering, Which; I now believe to be splash from the firing pin strike.
The recommendation for a harder thick cup primer in an auto loading rifle is more in the lines of safety rather than performance.