Maybe I’m crazy but look at this formula

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Cranky1

Cranky1

Member
Apr 18, 2018
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Jonesboro Il, United States
I know someone was figuring up a formulat for hunting power, I might have something

Grains x (velocity/100) Squared

now divide all that by diameter in inches times 100. 

so a 30 cal at 900 FPS with 44.74

44.75x(900/100) squared =3624.75/(.30x100)

120.825 units

100 mph Base ball

2242grn x (146.7/100) squared= 4825.98/(2.875x100)

16.78 units

Maybe I’m nuts but try it. 
 
I know someone was figuring up a formulat for hunting power, I might have something

Grains x (velocity/100) Squared

now divide all that by diameter in inches times 100. 

so a 30 cal at 900 FPS with 44.74

44.75x(900/100) squared =3624.75/(.30x100)

120.825 units

100 mph Base ball

2242grn x (146.7/100) squared= 4825.98/(2.875x100)

16.78 units

Maybe I’m nuts but try it.
Click to expand...

Why are you not wanting to use FPE as a metric? What is better about this or another equation vs FPE?
 
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There is a minor problem with the expression - the placement of your "equal" sign, but I understand what you mean; it's just an editing issue and not criticism. I did try it and it correctly placed one of my 25's lower than your 30. The other formula which was posted, attempted to introduce sectional density by multiplying length and diameter which might be ok if pellets were cylinders, but they are not - I will still give him partial credit. In order for this to be effective the ballistic coefficient must be calculated - I believe he admitted that his formula only predicted "muzzle" data. The baseball makes sense according to your expression or equation. Moral of the story - Mathematics is a language; be careful what you say or you might end up hunting with baseballs LOL! Thanks for info, and you are not crazy at all😃!
 
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Micro it was tough to type on my phone, and randy Johnson did smoke a bird with a base ball. Yeah this only works for the muzzle and bc and possibly fpe could be added in. I’m just a dumb construction worker, and this popped in my head sitting on the couch with my pup. 




HPAman I wouldn’t say it is better, just different. I think a 100fpe 30 cal would do better for hunting then a 100fpe 177. I feel the 177 would zip through vs the 30 punching a bigger whole transferring more energy. I mainly feel this way because we are not dealing with the kind of velocities that create explosive expansion. It’s like Roy weatherby vs Elmer Keith. 
 
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Micro it was tough to type on my phone, and randy Johnson did smoke a bird with a base ball. Yeah this only works for the muzzle and bc and possibly fpe could be added in. I’m just a dumb construction worker, and this popped in my head sitting on the couch with my pup. 




HPAman I wouldn’t say it is better, just different. I think a 100fpe 30 cal would do better for hunting then a 100fpe 177. I feel the 177 would zip through vs the 30 punching a bigger whole transferring more energy. I mainly feel this way because we are not dealing with the kind of velocities that create explosive expansion. It’s like Roy weatherby vs Elmer Keith.
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Use your formula and it will disagree with you. It will tell you that a 50fpe .177 (20 grain at 1058) will have 126 units as opposed to your 80fpe .30 producing 120 units.

44.75x(900/100) squared =3624.75/(.30×100)

120.825 units (44.75 @ 900 = 80.5fpe)

20 x (1058/100) squared = 2238.7/(.177x100)

126.4 units (20 @ 1058 = 49.7fpe)

If you use the same weight projectiles to get 100fpe it would be 44.75@1004 vs 20@1501

This makes the 30 cal 150.3 Units vs 254.5 Units for the 100fpe .177

Using the caliber as your divisor will cause the units to go up as the caliber goes down.
 
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Micro it was tough to type on my phone, and randy Johnson did smoke a bird with a base ball. Yeah this only works for the muzzle and bc and possibly fpe could be added in. I’m just a dumb construction worker, and this popped in my head sitting on the couch with my pup. 




HPAman I wouldn’t say it is better, just different. I think a 100fpe 30 cal would do better for hunting then a 100fpe 177. I feel the 177 would zip through vs the 30 punching a bigger whole transferring more energy. I mainly feel this way because we are not dealing with the kind of velocities that create explosive expansion. It’s like Roy weatherby vs Elmer Keith.
Click to expand...

Right. But the .177 can't produce that FPE because of the weight inside our velocities anyway.
 
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Micro it was tough to type on my phone, and randy Johnson did smoke a bird with a base ball. Yeah this only works for the muzzle and bc and possibly fpe could be added in. I’m just a dumb construction worker, and this popped in my head sitting on the couch with my pup. 




HPAman I wouldn’t say it is better, just different. I think a 100fpe 30 cal would do better for hunting then a 100fpe 177. I feel the 177 would zip through vs the 30 punching a bigger whole transferring more energy. I mainly feel this way because we are not dealing with the kind of velocities that create explosive expansion. It’s like Roy weatherby vs Elmer Keith.
Click to expand...

Use your formula and it will disagree with you. It will tell you that a 50fpe .177 (20 grain at 1058) will have 126 units as opposed to your 80fpe .30 producing 120 units.

44.75x(900/100) squared =3624.75/(.30×100)

120.825 units (44.75 @ 900 = 80.5fpe)

20 x (1058/100) squared = 2238.7/(.177x100)

126.4 units (20 @ 1058 = 49.7fpe)

If you use the same weight projectiles to get 100fpe it would be 44.75@1004 vs 20@1501

This makes the 30 cal 150.3 Units vs 254.5 Units for the 100fpe .177

Using the caliber as your divisor will cause the units to go up as the caliber goes down.
Click to expand...

Your right.... crap..... well it’s the first theoretical math I’ve done in about 14 years. Guess I should have ran more through it.... or maybe it’s a formula for penetration...yeah that’s it. Lol
 
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Intelligent construction worker I think...The most famous attempt I am familiar with was the Taylor KO, Taylor only considered diameter and did not include sectional density...but he was definitely on to something; "...First describing the Taylor KO Factor as "knock out value" or "strike energy" in his African rifles and cartridges, Taylor wrote that muzzle energy is "surely the most misleading thing in the world"...". https://en.wikipedia.org/wiki/Taylor_knock-out_factor

AAA Screenshot 285.1613700003.png



 
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Intelligent construction worker I think...The most famous attempt I am familiar with was the Taylor KO, Taylor only considered diameter and did not include sectional density...but he was definitely on to something; "...First describing the Taylor KO Factor as "knock out value" or "strike energy" in his African rifles and cartridges, Taylor wrote that muzzle energy is "surely the most misleading thing in the world"...". https://en.wikipedia.org/wiki/Taylor_knock-out_factor

AAA Screenshot 285.1613700003.png


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Yeah I was messing with it some. Maybe since pellets are not a cylinder diameter(or surface area of the face) and volume using water displacement could be used. 
 
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"Yeah I was messing with it some. Maybe since pellets are not a cylinder diameter(or surface area of the face) and volume using water displacement could be used." 

My thought is that these are attempts to quantify exactly where a particular combination falls within it's hunting purpose - that's good; and it's helpful. Most people can come up with comparisons, but plugging in the numbers and being able to determine exactly where it falls would be beneficial. A while back I came across this set of tests, linked below, from straight shooters "Our Take" of the Marauder which was very interesting; it does include specific BC data, too and energy figures - it's worth looking at. Notice how the energy for the 177 can match the 22 at 50 yards,, but the 25 is nearly double both - you have to scroll down the page: https://www.straightshooters.com/benjamin-sheridan-marauder-.25-wood.html
 
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Intelligent construction worker I think...The most famous attempt I am familiar with was the Taylor KO, Taylor only considered diameter and did not include sectional density...but he was definitely on to something; "...First describing the Taylor KO Factor as "knock out value" or "strike energy" in his African rifles and cartridges, Taylor wrote that muzzle energy is "surely the most misleading thing in the world"...". https://en.wikipedia.org/wiki/Taylor_knock-out_factor

AAA Screenshot 285.1613700003.png


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Agree with this. Ultimate value is the energy On Impact which can only be in projected as a value except with Doppler Radar (super accurate and they used to not have that). Even in subsonic speeds the wound channel is always larger than the caliber you are shooting, depending on not only the size but the shape and twist of the slug/pellet. Heck even the lead type matters.




 
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"Agree with this. Ultimate value is the energy On Impact which can only be in projected as a value except with Doppler Radar (super accurate and they used to not have that). Even in subsonic speeds the wound channel is always larger than the caliber you are shooting, depending on not only the size but the shape and twist of the slug/pellet. Heck even the lead type matters."

Yes, and I think we agree - if you looked at the straight shooters tables it's pretty obvious that different pellets which have the same ME may not at 50 yards...point is, they had to test it - there was no calculation except the BC from the data. We can pretty much guess what the results would be, but the 25 data shows how much more energy you can expect than 22 downrange and 177... Taylor's data on Wiki shows 458 vs 375 and IMO it is astounding. Still, I think Cranky1 is thinking like Taylor - is there a better way to calculate performance? I was just stating that you have to include density. This brings up another curiosity - why no 40 air guns? That's a semi rhetorical question - doesn't require an answer LOL - it's been fun! 
 
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Bc changes with velocity and distance plus the twist rates.....I think you would have to run a constant distance with constant twist rate and avg bc Something might be made from Fpe x diameter x bc 



too much theoretical for me. Now I’m gonna fix some coffee
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The issue is that no matter how you take the FPE and then × or ÷ by some other # it will always correspondly grow or shrink based on caliber size (to to weight). Where you could see this successful for an equation would be larger size .177 like a 14 grain .177 14 grain vs .22 14 grain traveling at the same speed. The shape being the same, the surface area would be your only difference and would indubitably show that a larger surface area must displace more material on impact. Here is where it gets dicey on the practical level, depending on the speed the .177 might penetrate or pass through, and the .22 land mid animal if we are talking small game. Some people like pass threws and some say the ideal situation is that the pellet goes most of the way through but doesn't exit the animal i.e. dumps its energy. To me it doesn't matter as long as the animal gets that knock down blow like you characteristically get when someone shoots a deer with a 30-06...down

So on that debate the surface area wins because it has more surface mass to displace and causes the animal to go down faster. When I open a quail up from a .177 sometimes I can't find the injury at first before removing the feathers. With a .22 I can see the wound right away. FPE is deceptive because a smaller caliber, imagine a needle, can go further into a mass with less force (.25 FPE imagine dropped from one foot) whereas a large caliber .50 couldn't go into a mass like ballistic gelatin until 60-100 FPE dropped from 1 ft.



All this to say FPE and practicality is what matters when the pellet hits the target. Sometimes smaller caliber can win out with accuracy when the grains are equaling that of a .22






 
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Formula this,don't be mattering if you can't hit what you are aiming at......sorry....head trips do result in many good inventions ;they should never be underestimated ....plus they come free,plus there will always be people telling you why they can't work,which can be a great thing if you listen before lighting the fuse on your home built cannon.
 
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