Muzzle Energy vs Recoil vs Rifle Weight for Dangerous Game

[zephyr]

Here is a good site to confirm the premise of this post .....
I used it when determining powders for my 505 Gibbs

ShootersCalculator.com | Recoil Calculator

An online calculator that calculates the recoil energy, impulse, and velocity of a firearm according to the firearm's weight, powder charge, bullet weight, and bullet muzzle velocity.

shooterscalculator.com

 

[Pheroze]

As for the cartridges I did not include, oh well… Look guys and gals, I selected what seemed the most popular cartridges or those representative of them.

I did notice the failure to include the very popular 400 H&H. You are forgiven. I will note that this wonderful cartridge will send a 400gr A-frame at 2350 fps with 81 grains of H4350... very reasonable recoil.

 

[Northern Shooter]

Excellent post! As much as these classic cartridges have an emotional aura surrounding them, I love seeing them quanitified to compare and contrast.

Is it true that the 470NE has a larger case capacity than the 500NE?

 

[MS 9x56]

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.

I have shot a 470NE once, that was enough for me. I have no use for any “magnum” cartridge. I have found the 9.3x 62 is comfortable for me and all the gun I need.

 

[Jim Golden]

For anyone that wants to compute their pet load....

Energy in foot pounds = 0.5 * (bullet weight in grains / 7000) * (velocity)^2 / 32.17

Example: .375 Weatherby with 300gr at 2885 ft/s (I've chrono-graphed two of mine and got 2885 and 2889 ft/s)

Energy = (0.5)*(300/7000)*(2885)^2 / 32.17
= 5544 ft-lbs


Knock Out Factor = (Bullet Diameter in Inches) * (Bullet Weight in Grains / 7000 ) * Velocity

KO = .375 * 300/7000 * 2885
= 46.36


The first one is Kinetic Energy.

The second is some kind of Momentum thing with Bore Diameter factored in.

I'm not sure I buy the Taylor Knock Out Factor. I get that a bigger bore imparts more energy (although it penetrates less). But it says a super slow 450/400 caliber with less than 75% of the energy has a much higher knock out factor that's 25% higher. A .378 Weatherby Magnum would only rate a 49 on this factor, which is less than a 450/400. The .378 is about nuclear. My .375 has an extra long barrel so I can approach .378 velocities.

It's the age-old argument of energy vs. momentum.

But anyway, with these two formulas, you guys can calculate any load you wish. It's really easy with a spread sheet. But you can do it with a calculator pretty easily too. No need to make Mark generate 10,000,000 combinations....ha ha!

I identify with Young Sheldon as well

 

[BlueFlyer]

Thanks Jim.

Just did a quick calulation to compare 2 cartridges that I hunt with regularly. The 280AI vs 45/70.

Same Energy but very different Knock Out score. This may be an extreme comparison but for me it does accurately describe the effectiveness of each cartridge.

The 280AI is fantastic on light to medium game with this projectile but anything heavier than 300Kg it is soso.
The 45/70 just poughs thru and gets the job done on heavier game. Especially when I bump the velocity just under 2000fps.

 

[BlueFlyer]

Hmm!

Just noticed the 378 Weatherby & 45/70 have the same KO score? Guess in this case Energy wins in this comparison. Guess you cannot look at either energy or KO score in isolation.

 

[CZDiesel]

My question is where my rifle comes in right now!
Winchester M70 458 Win Mag at 8lbs…
Hornady 500gr at 2150ftps
What kind of recoil energy and speed am I seeing? Just curious?

 

[BJH65]

Thank you Mr. Ouellette and fellow Marine for posting this interesting and helpful data. It very much benefits me since I’ve contemplated another rifle chambered in a cartridge more powerful than my 416 Rigby. Looking at the recoil of the 450 Rigby and even worse the 505 Gibbs, gives me the impression that the maximum recoil I can handle would likely be 458 Lott.

 

[BlueFlyer]

My question is where my rifle comes in right now!
Winchester M70 458 Win Mag at 8lbs…
Hornady 500gr at 2150ftps

 

[BlueFlyer]

Sorry

What kind of recoil energy and speed am I seeing? Just curious?

Sorry - did not do that calulation. I have found the formula to calulate - need the weight of powder if you know it?

 

[BlueFlyer]

Updated the spread sheet with the formulas published by SAAMI in th e"Gun Recoil - Technical publication July 9, 2018.

 

[grand veneur]

The Taylor KO factor is regularly cited. Whether such an antiquated theoretical value, like also the Shock Power Index from A-Square, are relevant in practice for the choice of a big bore rifle can be debated.

What kills a game is a bullet that penetrates deep enough in the right place and make a wound channel as large as possible. That's why the caliber, the bullet and the impact velocity of this are above all particularly important for the choice of a big bore rifle. At last there are personal factors such as interest for a cartridge and recoil tolerance.

 

[CZDiesel]

Sorry

Sorry - did not do that calulation. I have found the formula to calulate - need the weight of powder if you know it?

I do not know the weight of powder as it is factory Hornady loadings…
I just know it’s a 8lb rifle shooting a 5gr projectile at 2130ftps

 

[Altitude sickness]

For anyone that wants to compute their pet load....

Energy in foot pounds = 0.5 * (bullet weight in grains / 7000) * (velocity)^2 / 32.17

Example: .375 Weatherby with 300gr at 2885 ft/s (I've chrono-graphed two of mine and got 2885 and 2889 ft/s)

Energy = (0.5)*(300/7000)*(2885)^2 / 32.17
= 5544 ft-lbs


Knock Out Factor = (Bullet Diameter in Inches) * (Bullet Weight in Grains / 7000 ) * Velocity

KO = .375 * 300/7000 * 2885
= 46.36


The first one is Kinetic Energy.

The second is some kind of Momentum thing with Bore Diameter factored in.

I'm not sure I buy the Taylor Knock Out Factor. I get that a bigger bore imparts more energy (although it penetrates less). But it says a super slow 450/400 caliber with less than 75% of the energy has a much higher knock out factor that's 25% higher. A .378 Weatherby Magnum would only rate a 49 on this factor, which is less than a 450/400. The .378 is about nuclear. My .375 has an extra long barrel so I can approach .378 velocities.

It's the age-old argument of energy vs. momentum.

But anyway, with these two formulas, you guys can calculate any load you wish. It's really easy with a spread sheet. But you can do it with a calculator pretty easily too. No need to make Mark generate 10,000,000 combinations....ha ha!

I identify with Young Sheldon as well

For penetration, Momentum is what gets the work done. More so than KE

For bullet expansion I would think KE is important