although... the 500//416 necked down to 375 could make for some interesting velocities at minimal pressures.

We'd have to have a reamer made and no doubt the guns re-regulated, but we could rechamber an old barrel for kicks.

Heck, how much is a custom reamer? A couple hundred bucks?

I'm pretty sure i've got an extra 375 barrel... anyone interested?

Actually, it appears that the pressure for the 500/416 is higher than the belted 375.

39,885 psi (2,750 bar), Copper crusher method
44,962 psi (3,100 bar), Piezzo method
Bullet: Woodleigh softpoint and solid 410 grs (26.6g)
Velocity: 2,330 ft/sec (710m/s)
Energy at muzzle: 4,940 Ft lb (6,700 J)