1. Assume a very stoutly built .416 Rigby case, or a .338 Lapua case necked up to .416.

2. Assume a 300 grain monometal bullet.

3. Assume 60,000 - 65,000 psi.

4. Assume a 24" Barrel.

How fast at the muzzle?

Thanks,

lawndart

Identical to 30-378 Weatherby

very FAST!!! should be somewhere between 2900 to 3200 fps.....
jus my 2 cents..

zubin

338 Lapua necked is about 61,000 PSI and would be about 2900fps.

steve

Depending on the powder, you could expect to see as high as 3360 at 62000psi (xmr-3100 calculated load data), but only 3050fps with the next fastest powders (H4350, H4831, ADI AR 2217 again all calculated, not actual)

Bro'lawndart,
Having played with the .416 Rigby some, I know that 2900 fps is reasonable with the various 4350's and VVN550 around 104 to 105 grains.
I think AccuLoad would put this in the 60Kpsi neighborhood.

I never found the .416/300gr X-Bullet very accurate, and preferred the 350 grainer at 2700 fps from the .416 Rigby. From there, I underwent the evolution to .375 Lapua, which the Germans were doing as the 9.5mm Tornado, in 2001.

That 300 grain X-Bullet load in a .416/.338 Lapua Magnum would be 3.542" COL, so would fit in a .375 H&H length action, and likely be more "efficient" than the .416 Rigby.

You could probably do 2900 fps easily enough with the .416 Lapua and 300 grainers. Maybe 3000 fps on the ragged edge, like Weatherby loads theirs.

If you are thinking of taking longer shots with it, a slighly longer bullet will give better results. Given the requirements of freebore, case neck length and a halfway decent nose length on the bullet, a 300gr bullet just does not cut it on BC. Go a little longer on the bullet and the extra BC translates into a lot more performance downrange.

Yeah,

I'm no fan of low SD bullets, but what the client wants the client gets . Their numbers were derived from the computer and not actually shooting that combination. I had to quelch their "optimism".

Thank you all for your help.

lawndart

Jeeeeze Louise, those guys can't shoot...

Basically a .416 version of the .338 LAPUA. WITH A 24 INCH BARREL and good powder selection, I'll bet 3000fps at 62000KPsi. Take a .416 wby mag, turn off the belt and load to equal pressure and bullet weight in a std .416 Rigby.-ROB

Hi Lawndart,
Here is some information for you from the Barnes Reloading manual
300 grain X bullet Max velocity 3059 fps 6198 Ft Lbs of energy
325 grain X bullet Max velocity 3011 fps 6495 Ft Lbs of energy
350 grain X bullet Max velocity 2891 fps 6536 Ft Lbs of energy
400 grain X bullet Max velocity 2714 fps 6475 Ft Lbs of energy

With all bullets sighted at less than 2 inches high at 100 yards the 300 yard bullet drop numbers are as follows:
300 grain X bullet -6.97 inches 3657 Ft Lbs of energy
325 grain X bullet -6.92 inches 4163 Ft Lbs of energy
350 grain X bullet -7.31 inches 4372 Ft Lbs of energy
400 grain X bullet -8.24 inches 4368 Ft Lbs of energy

So for 1.27 inches of drop your giving up just over 700 ft lbs of energy
The difference in the numbers gets larger as the distance is increased to 400 yards
Bullet drop numbers:
300 grain X bullet -20.48 inches 3030 Ft Lbs of energy
325 grain X bullet -20.08 inches 3559 Ft Lbs of energy
350 grain X bullet -21.06 inches 3797 Ft Lbs of energy
400 grain X bullet -23.63 inches 3806 Ft Lbs of energy
So if you look at all the numbers your clients would have been better off to go with the 350 grain bullet which shows the best returns as far as energy and bullet drop go.
Take good care,
Dave

One good thing about this job is I get to explore areas that I would never have looked into on my own dime. I had better get cracking on building a bullet catch box. All I know is it will be long and deep.

lawndart

Thanks for the new numbers gents.