Minimum Loads for a 378 Weatherby

[bhempfli]

I came into a used 378 Weatherby years ago with the intent of taking it to Africa when I got older and could afford it. Now that I am actually able to go to Africa, I no longer want to shoot full power 300 gr loads at close to 3000 fps.

I have tried to find data that would allow me to take the 300 gr bullet down to 375 H&H levels but there are very few. Hodgdon has a load with 4350 that gets it down to just under 2600 fps but that is just a shade faster than I want to go.

Hodgon's maximum load is 100 grains, their starting load is 95 grains as listed on their website. Would the rule of thumb of reducing a max load by 10% and starting there work in this instance? It would lower the starting load to 90 gr which would allow me to come up just a bit and find that sweet spot in the 2400 to 2500 FPS.

Thanks in advance for any shared knowledge here

 

[Gb300wm]

You have to be very careful with large capacity cases and down loading them. It could cause hang fires or dangerous over pressure conditions. It’s best to use manufacturer tested data. In this case, maybe a 375 h&h would be your ticket…

 

[bhempfli]

Thanks for the reply. Yes, I do worry about the size of the case. I may just run with it at 2600 fps

 

[wboggs]

You could also use a lighter bullet, say a Barnes or put a brake on it.

 

[Murray Brook]

Another word of advice would be to always use the Fed 215 primer. I never loaded for the 378 Wea but have a 30/378 ( same case) and the only primer that didn't give me hang fires or pressure spikes of the ones I used was the Fed 215.