Quick and dirty internet search, I won't vouch for the accuracy of the data:
7.62cm 17pdr
Projectile weight: 7.7 kg (AP)
Sectional Density: 1.886
Muzzle Velocity: 883 m/s
Total Kinetic Energy: 3001 KJ
Kinetic Energy pr. cm^2: 65.8 KJ
7.6cm M1 L/55
Projectile weight: 7.0 kg (APCBC)
Sectional Density: 1.724
Muzzle Velocity: 792 m/s
Total Kinetic Energy: 2195 KJ
Kinetic Energy pr. cm^2: 48.38 KJ