Eric Anderson
AH enthusiast
So I was looking at maybe purchasing a Montana rifle chambered in .404 Jeffry.
Then I started looking at what I had vs what I would be getting, and charted it out.
For a .375 Ruger with 300 grain bullets
Energy. 4,713 ft/lbs
SD .304
Frontal area .110 square inches
.404 Jeffry with 400 grain bullets
Energy 4,698 ft/lbs
SD .320
Frontal area .139 square inches
Energy was taken from Wikipedia
I used 300 grain for the .375 because that is standard DG solid 270 grain has more energy but I don’t know if any 270 grain solids
I used 400 grain for Jeffry because the listed energy for 450 was much lower due to much lower velocity. 350 grain gave up a lot of SD.
I used frontal area for solids instead of softs because expansion can be pretty inconsistent from shot to shot on softs.
So looking at the numbers, they are equal in energy 15 ft/lbs is negligible.
The .404 has 5% better sectional density, which is a small, but consistent gain.
Frontal area is the only thing that the .404 has a big leg up on the .375. A 20% gain is big
This leaves me confused though. I have always heard and believed that the .40 calibers, and the .404 in particular hit a buffalo a lot harder than a .375
Just looking at the data though, I don’t understand why. 5% better SD and 20% bigger Frontal area is definitely a step up, but shouldn’t be a night and day difference.
So why does the 404 hit so much harder? Is it something I haven’t considered?
Then I started looking at what I had vs what I would be getting, and charted it out.
For a .375 Ruger with 300 grain bullets
Energy. 4,713 ft/lbs
SD .304
Frontal area .110 square inches
.404 Jeffry with 400 grain bullets
Energy 4,698 ft/lbs
SD .320
Frontal area .139 square inches
Energy was taken from Wikipedia
I used 300 grain for the .375 because that is standard DG solid 270 grain has more energy but I don’t know if any 270 grain solids
I used 400 grain for Jeffry because the listed energy for 450 was much lower due to much lower velocity. 350 grain gave up a lot of SD.
I used frontal area for solids instead of softs because expansion can be pretty inconsistent from shot to shot on softs.
So looking at the numbers, they are equal in energy 15 ft/lbs is negligible.
The .404 has 5% better sectional density, which is a small, but consistent gain.
Frontal area is the only thing that the .404 has a big leg up on the .375. A 20% gain is big
This leaves me confused though. I have always heard and believed that the .40 calibers, and the .404 in particular hit a buffalo a lot harder than a .375
Just looking at the data though, I don’t understand why. 5% better SD and 20% bigger Frontal area is definitely a step up, but shouldn’t be a night and day difference.
So why does the 404 hit so much harder? Is it something I haven’t considered?