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?
@CZDiesel , I posted the link to shooterscalculator.com at least twice in my posts.
@zephyr , also post the same link for "just such an emergency"
Here is a good site to confirm the premise of this post .....
I used it when determining powders for my 505 Gibbs
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
The online calculators make this stuff really easy!
Since we do not know the exact weight of the powder charge in your Hornady factory ammo, I used 70 grains from my H4895 loads. Chances are Hornady's loads are a little heavier on powder, making for a compressed powder charge. It still goes bang!
Also, it is ALWAYS good to clock the muzzle velocity of all loads, factory or hand loads. I've measured some 458 Lott factory ammo where on its box listed MZ of 2300, only to find the velocity was 2150. I am not kidding on that!
The chart above with data calculated using shooterscalculator.com , shows your 8 lb. rifle's free recoil energy of 80.5 lbs exceeds that of a 10.5 lb. 458 Lott and is comparable to a 10.5 lb. 470 Nitro Express that burns 60% more powder! Everything traveling down the barrel, i.e. bullet and weight of powder charge is referred to as "ejecta". The ejecta total weight affects free recoil.
For fellow shooting nerds, here's a simple article from Outdoor Life concerning shotgun recoil. The concept is the same for rifles.
There are two different types of recoil that are important to shotgun shooters: free and felt recoil. Understanding both will help accuracy.
www.outdoorlife.com
“There are two kinds of recoil shotgunners care about. The first is the free recoil that the mathematic formula gives us. The second is the perceived recoil (aka felt recoil), which is the cause of a swelled cheek and sore shoulder (i.e. the recoil you feel). They are different, but free recoil is directly related to perceived recoil.
While there are several free recoil formulas, I like the one from powder maker Hodgdon. It includes the
weight of the gun, the weight of the
ejecta (shot, wad, and powder), and the
speed of the ejecta.
The formula for recoil energy in ft./lbs. is:
(Bw Mv + 4,700 Pw)2 / (64.348 Gw) where:
Bw = weight of the ejecta (shot and wad) in pounds;
Mv = muzzle velocity in feet per second;
Pw = powder weight in pounds; and Gw = the weight of the gun in pounds.”
The above excerpt from Outdoor Life clearly identifies defines the “ejecta” as everything that leaves a gun’s chamber to include the weight of the powder. A heavier powder charge does increase recoil. That’s why if all else is equal, a 416 Rigby produces more recoil than does a 416 Remington. The Rigby was designed to operate with low pressure in the era of Cordite gunpowder which was very temperature sensitive. Even on the hottest day in Africa, where the pressure produced in an old 416 Rigby far exceeded its mean working pressure (47000 psi), the bolt will still function for a second shot! My SWAG (sophisticated wild ass guess) is a Rigby's bolt would open with 65,000 psi, if not a little more.
For comparison, here is a recoil calculator for shotguns:
http://www.omahamarian.org/trap/shotshellenergy.html
It calculated for a heavy 12 ga magnum 1.5 oz load at 1350 fps muzzle velocity at 44 lbs free recoil:
One can add ejecta weight or increase velocity but a 12 ga, 8 lb. shotgun will not produce the same level or recoil as a 10.5 lb. 458 Winchester! But firing three rounds quickly from this shotgun will definitely get one's attention!
Bonus: Here's a good article on the 416 Rigby;
Designed from the ground up by William Rigby of the British firm John Rigby & Co., the .416 Rigby matched the power of the .404 Jeffery while also being compatible with bolt-action feed systems.
www.americanrifleman.org
