Is it possible to match the ballistics of the 338-378 Weatherby to the 338 Excaliber. For instance to take the 250 grain bullet from 3060fps. to 3250 of the Excaliber?

As the two cartridges have pretty much the same internal capacity, I would expect the ballistics to be identical. The only real differance that I can see is that the Wby has more free bore then the Excaliber, which theoretically should give the nod to the Wby, speed wise. I don't know how A-Square manages to get higher published velocities then everyone else with cases that have the same capacity. I would take such claims with a grain of salt until I saw the results across the chronograph. FWIW - Dan

I have no idea what is going on about factory ammo for both cartridges, but the following are the ballistics:

8.59 (.338) Titan
La. ammo: 185-gr NOS = 3550 fps
Lazzeroni: 225-gr NOS = 3300 fps
Lazzeroni: 250-gr A = 3150 fps

.338-378
Wby. ammo: 225-gr X = 3100 fps
Wby. ammo: 250-gr NOS = 3060 fps

The 338 Excaliber isn't the same cartridge as the Lazzeroni 8.59 Titan (at least I don't think so, although I seem to recall that they are pretty close in case capacity as well). I believe the 338 Excaliber started life as a 416 Rigby. Lazzeroni designed his own case, but it ended up being damn close to the 416 Rigby. Also keep in mind that the Lazzeroni stuff is usually run at much higher pressures then pretty much anything else. FWIW - Dan

The Excaliber will out do the 338-378 with a 250 grain bullet but, when you go say to 300 it gets the edge.

You could have your Wby rechambered for the Excaliber.