Bullet Seating Depth Effect On Case Volume?

[9.3x64]

According to xxlreloading.com, below are case capacities and standard CAOL measurements for four different 7mm cartridges.

280 Remington 67.9 grains of water. 84.6mm CAOL.
7x64 Brenneke 69 grains of water. 84mm CAOL.
280AI 74 grains of water. 84.6mm COAL.
7mm Remington Mag 82 grains of water. 83.6mm CAOL.

I have loaded the 7x64 Brenneke for about 20 years. My favourite load with the 160 grain Nosler Accubond is seated to 87mm. 3mm longer than the standard CAOL. The Blaser R8 magazine length is very generous.

My load is way over book maximum loads, yet I have fired a thousand rounds with this load and get good case life, and no signs of excessive pressure. Bolt cycling and extraction has always been 100% reliable.

Does anyone know how much difference that extra 3mm CAOL makes on “usable” case capacity?


Would anyone with Quickload be kind enough to tell me what the estimated maximum load and velocity would be for the below combination would be?

7x64 Brenneke
Blaser R8 22 inch barrel
160 grain Accubond
CAOL 87mm
Powder 2209 / H4350
RWS cases
RWS 4351 Primers
RWS / GECO cases

Thankyou Allan