.280 Enfield...Ahead of its time

[stanc]

The .280 pushing a 7mm 168 VLD type bullet versus the 7.62 pushing a M118 173gr Special Ball leans in favor of the 7mm, and makes it a true 800m cartridge. That is with the 7mm 168 VLD starting 100fps slower at 2400fps and the M118 at 2500fps, which is book value for the M24 Sniper Rifle.

With the .280/30, we are looking at faster velocities that make the 7.62 NATO not worth looking at, and you have bullets of similar weights, similar velocities, with the sectional density and aerodynamic advantage clearly in the 7mm's favor. I just ran the numbers side-by-side with the G7 BC values for a 168 7mm VLD at .313, and the M118's .240 G7 BC. The 7mm retains 911 joules at 800m, while the 7.62 M118 only retains 692 joules at that range, having started 100fps faster at the muzzle.

Unfair comparison. AFAIK, the US and UK have never used VLD bullets in infantry rifle calibers.

Try 7mm 168gr FMJ (w/tangent ogive) against M118SB.

(And your 2400fps MV seems a trifle optimistic, seeing as how the long, 168gr bullet would reduce powder volume.)