Author Topic: Small bore power comparison question.... (Read 1173 times)

markp · « **on:** January 20, 2011, 03:51:27 PM »

If the .223 starts a 60 grain nosler partition at 3100 fps and the .243 starts the 100 grain nosler partition at 2900 fps What percent of power would the
243 have over the 223 ? If the velocity were identical I would call it 40% because the bullet has 40% more weight. Not knowing how to factor in the differance in velocity I would call it 35%.

drdougrx · « **Reply #1 on:** January 20, 2011, 04:10:53 PM »

I'm assuming power = Terminal Energy???

Could you calculate terminal energy for each and then knowing the difference, determine the % increase in TE???

ironglow · « **Reply #2 on:** January 20, 2011, 04:16:28 PM »

Here's a calculator you can put in your favorites lis ..and figure fpe for yourself...
http://pyramydair.com/site/articles/formulas/

PowPow · « **Reply #3 on:** January 20, 2011, 04:20:49 PM »

Kinetic energy = 1/2 * mass * (velocity*velocity) i.e (velocity squared)

for comparison purposes:
100*2900*2900/60*3100*3100= 1.46 i.e, the 243 has 46% more kinetic energy than the 223

at the same velocity (doesn't matter what the velocity is, its the same) the 243 kinetic energy is 100/60, or 166% of the 223, or 66% more.

ironglow · « **Reply #4 on:** January 21, 2011, 04:22:25 AM »

According to the Pyramyd calculator;
60 gr @ 3100 = 1280.65 ft lbs
100 grs @ 2900 =1867.89 ft lbs

As far as practical application, it of course doesn't end there. There is also bullet type, frontal area (meplat) etc to consider in plotting terminal performance.

Catfish · « **Reply #5 on:** January 21, 2011, 02:22:21 PM »

I think the best way to figure the preformance is the Taylor Knock formular. Konetic energy is a very poor way to figure knock down power because it squares velocity and use only 1/2 the mass of the bullet. His formual is vel. x weight in gr. x dia. of the bullet divided by 7,000. Taylor was a big game guide in Africa. He also said the the larger the dia of the bullet the better.

shot1 · « **Reply #6 on:** January 22, 2011, 06:25:27 AM »

After shooting many many hundreds of game animals with about everything from and arrow up through a 45-70 I have come to the conclusion that all that hype about foot pounds of energy etc. is just HYPE. Killing game is about putting the proper projectile in the proper place, heart, lungs, CNS that will end life as we know it. I have never seen a game animal actually knocked down by the power of the bullet alone. They drop in their tracks because of CNS being interrupted of they jump doing back flips etc. from CNS reacting from tissue being displaced and bone being traumatized by the bullet. When you shoot a big game animal with a bullet going several hundred to a few thousand fps that packs tons of "energy" if it had "knock down power" it would flatten everything ever hit anyplace. If you believe in knock down power take a 25 pound sack of sand and set it up on a flat surface and shoot it with your favorite big game round and see if it knocks it off on to the ground.

243dave · « **Reply #7 on:** January 22, 2011, 12:02:55 PM »

Quote from: shot1 on January 22, 2011, 06:25:27 AM

After shooting many many hundreds of game animals with about everything from and arrow up through a 45-70 I have come to the conclusion that all that hype about foot pounds of energy etc. is just HYPE. Killing game is about putting the proper projectile in the proper place, heart, lungs, CNS that will end life as we know it. I have never seen a game animal actually knocked down by the power of the bullet alone. They drop in their tracks because of CNS being interrupted of they jump doing back flips etc. from CNS reacting from tissue being displaced and bone being traumatized by the bullet. When you shoot a big game animal with a bullet going several hundred to a few thousand fps that packs tons of "energy" if it had "knock down power" it would flatten everything ever hit anyplace. If you believe in knock down power take a 25 pound sack of sand and set it up on a flat surface and shoot it with your favorite big game round and see if it knocks it off on to the ground.

I haven't killed the amount of game you have but I agree 100%. The belief that knockdown power really knocks things down is like believing in unicorns and honest politicians.

Flynmoose · « **Reply #8 on:** January 22, 2011, 07:37:59 PM »

I totally agree with the part about honest policticians.......jury is still out on the unicorns though.
FM

stubshaft · « **Reply #9 on:** January 22, 2011, 07:43:27 PM »

Quote from: shot1 on January 22, 2011, 06:25:27 AM

After shooting many many hundreds of game animals with about everything from and arrow up through a 45-70 I have come to the conclusion that all that hype about foot pounds of energy etc. is just HYPE. Killing game is about putting the proper projectile in the proper place, heart, lungs, CNS that will end life as we know it. I have never seen a game animal actually knocked down by the power of the bullet alone. They drop in their tracks because of CNS being interrupted of they jump doing back flips etc. from CNS reacting from tissue being displaced and bone being traumatized by the bullet. When you shoot a big game animal with a bullet going several hundred to a few thousand fps that packs tons of "energy" if it had "knock down power" it would flatten everything ever hit anyplace. If you believe in knock down power take a 25 pound sack of sand and set it up on a flat surface and shoot it with your favorite big game round and see if it knocks it off on to the ground.

I agree with you 110%.

For a real eye opener shoot the same bag with an arrow and watch it zip right through.

shot1 · « **Reply #10 on:** January 23, 2011, 03:01:47 AM »

It will do the same to a kevlar (SP?) vest.

helotaxi · « **Reply #11 on:** January 23, 2011, 06:30:29 PM »

Quote from: Catfish on January 21, 2011, 02:22:21 PM

and use only 1/2 the mass of the bullet. His formual is vel. x weight in gr. x dia. of the bullet divided by 7,000.

Then by your logic that the 1/2 in the KE formula matters when talking comparative energy, the Taylor formula only uses 1/7000th of the bullet diameter...just like the 7000, the 1/2 is a constant and can be ignored for comparative purposes. The Taylor formula uses the 7000 to make the conversion between grains and pounds. The 1/2 in the KE formula is nothing more than a constant and applies to the product of the mass and the square of the velocity, as such it neither applies to to the mass nor the velocity square.

markp · « **Reply #12 on:** January 24, 2011, 02:39:56 AM »

Re: Small bore power comparison question....
« Reply #4 on: January 21, 2011, 09:22:25 AM »

Reply with quoteQuote
According to the Pyramyd calculator;
60 gr @ 3100 = 1280.65 ft lbs
100 grs @ 2900 =1867.89 ft lbs

As far as practical application, it of course doesn't end there. There is also bullet type, frontal area (meplat) etc to consider in plotting terminal performance.
ironglow

The pyramyd calculator seems to support my belief then that with this load the .243 has aproximatley one third more power.

This is all I am trying to do it find a way to look at the .243 in relation to the .223 powerwise. Thanks Ironglow

helotaxi · « **Reply #13 on:** January 24, 2011, 02:09:20 PM »

The long and the short of the comparison is that they are in totally different classes. Energy notwithstanding, the staggering variety of bullets available for the .243 makes it a much more effective cartridge on thing bigger than varmints and on varmints at longer ranges.

ironglow · « **Reply #14 on:** January 27, 2011, 06:05:53 AM »

It becomes abundantly obvious that speed/weight is not what governs terminal performance when we take a serious look at the old favorite..22 LR !
I am now 74, and I have hunted woodchucks since I was about 12; for the most part with .22 LR . From that experience (and hundreds of deceased chucks) I can assure you there is little comparison between the wound channel of a round nose and hollow point. The more "hollow" the point it seems, the greater the wound channel...but of course, I don't really have to tell experienced .22 LR hunters about that .

That is precisely why when I buy bulk cartridges I opt for the Winchester X-perts rather than the Federal bulk hollowpoints. The
Federal hollowpoints are barely 'hollow'.. just a dimple...while the X-perts are a deep, gaping hollow point, and only do 1220 fps (while the Federals do 1260)....and they each make wounds which are comparable to their hollow points on woodchucks.

http://www.midwayusa.com/viewProduct/default.aspx?productNumber=358933