Muzzle Energy vs Recoil vs Rifle Weight for Dangerous Game

Some members have shot 50 or more species of African animals with one rifle, in most cases a .375 H&H. I am not one of them. I have loved firearms since 1972 and since then, seem to have collected more than I need. Concerning dangerous game (DG) rifles chambered in .375 H&H and more powerful cartridges, I have more than I have safaris that I will take. Of my rifles of different chamberings (cartridges), for any safari I must decide on what cartridges I need or perhaps want to use for dangerous game.

The table below is a simple comparison of attributes of DG cartridges based on common factory and hand loads. Notice that the lowly .375 H&H has 4300 ft. lbs. of energy! With proper shot placement this will kill large elephants has has done so since 1911! For a 10.5 lb. rifle (total weight of loaded rifle with scope and sling, if any) the recoil generated in slightly less than 40 lbs. at a rearward velocity of 15.65 FPS. While this is twice that of a lighter 30-06, it is very manageable by most adult men and many women.

Increasing total rifle weight by one pound or slightly more than 9% also reduces the recoil by 9%. For a .375 this may not seem like much but reducing recoil of a 458 Lott or 500 Nitro by 9% will be noticeable by most shooters! Also, for rifles with the same total weight, the 470 Nitro popular in modern double rifles has twice the recoil energy as does the 375.

Decreasing bullet weight or selecting a faster burning powder that requires less weight to produce the same velocity will reduce recoil.

View attachment 622873

Looking at the 458 Winchester we find the old standard of 5000 ft. lbs. of energy at 2150 muzzle velocity. This was what the much older 450 Nitro produced which was very effective on elephants. All but two of the listed cartridges generate near or over 5000 ft. lbs. of energy. Even the 404 Jeffery has 4700 ft. lbs. of energy. No wonder it has such a great reputation as an effective DG killer. Let us not forget that even the somewhat lower power 375 H&H and 450/400 have taken more than their fair share of elephant and other dangerous game! Power (like speed) is good, accuracy is final!

Some cartridges such as the 404 Jeffery created in 1906 and the 416 Rigby from 1911 have greater muzzle velocity and power than when created. They are now loaded with much better gunpowder than the temperature unstable Cordite of their era. As for their killing effectiveness, the bullets available today are much more effective than those of a century ago!

Don’t forget bore diameter in relation to killing effectiveness. That’s the secret to John Taylor’s rating of Knock Out Blow (or factor), bore diameter times projective weight times velocity, divided by 7000,
i.e. (.375 x 300 x 2250)/7000 = 40

The Knock Out Blow makes sense in the greater the bullet diameter, the faster transfer of energy to the target. This also explains why all other things being equal and with the same muzzle energy, a smaller .416 Rigby even with 20% less bullet weight, will penetrate further than the larger .458 Winchester.

Please use this simple table to compare muzzle energy and its inverse, recoil energy and velocity. Hopefully all will find their happy balance of a powerful, personally accurate rifle at a good carry weight for their dangerous game safari!

Note: Above information is intended for those who are trying to wrap their brains around all of this. I hope it helps!
Really like your chart Mark!!!! As usual your attention to detail is exceptional! The only thing both of us know and many others using the 470 as the example I can use RL 15.5 at 84 grains to get 2150 FPS versus the powder you show at 115 grains with my load producing a significant reduction in felt recoil with no loss of foot pounds of force. On another note when is your and your lovely wife’s next trip to Africa?
 
That's significant difference in recoil regarding the 84gr vs 115gr 470NE loads.

67.51 ft-lbs vs 82.23 ft-lbs.

Even less considering most 470NE doubles will be in the 11lbs range.
 
I think the concensus now is 404 Jeffery was developed in 1905.

The one I built weighs right at ten pounds loaded with four cartridges. The recoil may be  relatively modest but still all I can handle ... and I'm no lightweight. If this gun will kill an elephant, I can see absolutely no reason to own anything larger. It's more than enough gun for me.
1904… hence the name.
.40 of 1904 like .30 of 1906…
 
That's significant difference in recoil regarding the 84gr vs 115gr 470NE loads.

67.51 ft-lbs vs 82.23 ft-lbs.

Even less considering most 470NE doubles will be in the 11lbs range.
You are correct!!! If you are a reloader this is important. Ken Owen taught me this with @rookhawk backing it up then my own experience confirming it
 
1904… hence the name.
.40 of 1904 like .30 of 1906…
That's the first time I have heard that explanation. From what I've read, for the longest time it was thought the cartridge originated in 1907 or 1909. A letter dated 1905 was found to Jeffery Company from an Indian prince commenting on how well his 404J performed. I seem to recall some ads were also found for 1905. Last I knew the old company records are now owned by someone in Texas who isn't sharing. Early company history is a bit of a mystery. One explanation for the naming of the cartridge is Jeffery was wary of introducing a cartridge with a bullet even remotely close to .45 caliber as British govt had banned export of any former military calibers to the colonies. Restless natives were reloading with whatever they could find in their surplus military guns they had either stolen or picked up on the black market. I suppose it is conceivable someone could hollow out the base of a .423 bullet (like a Mine ball) and maybe make it work in .45 barrel. Would be pretty tough to make a 40 caliber bullet work, hence choosing to describe the new cartridge less than accurately as something 40 caliber-ish. Anyway, that's one explanation I've read. Admittedly not a good one.
 
I was playing around with my 500 Jeffery over the weekend.
Instead of using a slower burning powder with around 118-120 grain powder charge, I used a faster burning powder (AR2208) with a much smaller powder charge at 100 grains and a foam case filler. I also got the weight of the rifle up from 10.9lbs to 11.66lbs. Between the smaller powder charge and the increased weight of the rifle the felt recoil was reduced significantly, much more than I was expecting. For a 500 calibre it is quite comfortable to shoot.
Crunching the numbers gave me the following
92.7ft/lbs of recoil energy with the rifle at 10.9lbs and a powder charge of 118 grains
78.7ft/lbs of recoil energy with the rifle at 11.66lbs and a powder charge of 100 grains
 
Given the scenario you presented (15 gns, 75fps and 3ft/lbs of difference), you felt or perceived recoil should be very similar. I would guess that the 125 gn load would have slightly more actual recoil. All else being equal, you'll feel the heavier bullet more.
 
I was playing around with my 500 Jeffery over the weekend.
Instead of using a slower burning powder with around 118-120 grain powder charge, I used a faster burning powder (AR2208) with a much smaller powder charge at 100 grains and a foam case filler. I also got the weight of the rifle up from 10.9lbs to 11.66lbs. Between the smaller powder charge and the increased weight of the rifle the felt recoil was reduced significantly, much more than I was expecting. For a 500 calibre it is quite comfortable to shoot.
Crunching the numbers gave me the following
92.7ft/lbs of recoil energy with the rifle at 10.9lbs and a powder charge of 118 grains
78.7ft/lbs of recoil energy with the rifle at 11.66lbs and a powder charge of 100 grains

That's my experience as well I use H4895. My 500 Jeffery weighs 12 lbs with scope unloaded. Shooting a 570g bullet at 2300 fps, recoil is sporty but not punishing.
 

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