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Kinetic energy Hevi vs. Lead

Started by jfair, April 20, 2011, 09:29:38 AM

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jfair

Man I'm addicted to this board.  Kinetic energy is defined as (mass x velocity squared) / (2).  I don't believe what I read until proven so here go the numbers.  Lead in grams per pellet in 4,6,7 shot respectively - .21310, .12910, .9700.  Hevi-13 in grams per pellet 4,6,7 respectively - .24516, .19282, .14852.  Velocity of the lead will vary with load, but I used 1200 fps.  Heavi-13 is 1090 fps.  So with physics, here are the results in foot pounds of kinetic energy:

Lead               4 = 10.5      6 = 6.4      7 = 4.1
Hevi-13           4 = 10.0      6 = 7.9      7 = 6.1

The big advantage I see in Hevi is the pellet count.  Remember this is energy per pellet.   Energy is only transferred completely if the pellet does not exit the target.  Those that blow right through a bird transfer only part of their energy, the rest is wasted.  Take it for what it's worth but this was eye opening for me.  The 40% more energy claim does not hold water unless you are counting on more pellets hitting the target.

jfair

#1
Quote from: slickyboyboo on April 20, 2011, 10:00:45 AM
You also must consider the hardness of the shot, being Hevi is much harder than lead, and therefore doesn't deform, resulting in better penetration, even with 1-2 shot sizes smaller.

Also there is no such thing anymore as Hevi-13, it is all regular 12 g/cc Hevi-shot. This was confirmed by one of the VPs at EM.

My point exactly.  Lead will most likely transfer most of its energy by "mushrooming" and staying with the target.  Hevi will not mushroom.  Much like shooting solids in a rifle.  Could be good, could be bad.  That is another discussion.  The numbers for mass that I used are, I believe, up to date for the newer Hevi.  I'm not trying to go against the flow, just trying to put the facts out there.

If my numbers are wrong then the Hevi mass is too high.  The energy in turn would be even lower.

JUGHEAD

Another thing you didn't consider in your calculations is down range velocities and what the KE at those ranges will be.  A heavier projectile, with the same aero profile, will lose it's velocity at a slower rate down range due to higher momentum.  Number at the muzzle don't mean a whole lot.  Not trying to nit pick....just something else to ponder as you think through all of it....

new2turkey

Quote from: JUGHEAD on April 20, 2011, 10:28:52 AM
Another thing you didn't consider in your calculations is down range velocities and what the KE at those ranges will be.  A heavier projectile, with the same aero profile, will lose it's velocity at a slower rate down range due to higher momentum.  Number at the muzzle don't mean a whole lot.  Not trying to nit pick....just something else to ponder as you think through all of it....


Very true... Think about hitting a golf ball with a club, and then a ping pong ball.

You strike both at the same speed, and the ping pong ball slows right down, and curves all over the place...



Better patterns and holding velocity...

jfair

#4
Quote from: slickyboyboo on April 20, 2011, 10:36:29 AM
JUGHEAD, very true! A heavier pellet of the same size will bleed off speed and therefore energy much slower, and thus need less velocity at the muzzle to acheive the same energy and penetration downrange.

Proper wieght of Hevi pellets (Hevi-13 or Hevi-shot, both are the same) should be:

#4 - 0.22630
#6 - 0.13710
#7 - 0.10300

Thanks for the info.  New calculations would then be:

Lead             #4    10.5              #6       6.4           #7          4.1
Hevi              #4     9.2               #6       5.6           #7          4.2

You guys are right about downrange velocities.  Do not take it as nit picking at all.  It needs to be considered.  I wish I could find some data on say velocity at 40 yards.  Both will decrease, so these numbers are both obviously a little high past initial muzzle velocity.  Trying to do the calculations myself is a logistical nightmare.  Too many variables!  I will be shooting the Hevi's this year, but the math has me leaning toward the mag blends with the increased velocity.   Thoughts?

stinkpickle

Quote from: jfair on April 20, 2011, 10:58:40 AM
...I will be shooting the Hevi's this year, but the math has me leaning toward the mag blends with the increased velocity.   Thoughts?

I would go with the increased pattern density of straight #7's, even at the lower velocity.  I've twice witnessed a low-flying #7 pellet completely penetrate the breast and end up under the skin on the OPPOSITE side of the bird...both times in the 35-40 yard range.  That's plenty of oomph!  ;)

jfair

I would go with the increased pattern density of straight #7's, even at the lower velocity.  I've twice witnessed a low-flying #7 pellet completely penetrate the breast and end up under the skin on the OPPOSITE side of the bird...both times in the 35-40 yard range.  That's plenty of oomph!  ;)
[/quote]

You are right about pattern density.  I have a box of 7's and mag blend on the way to try them.  Only have shot the 6's and am around 180 pellets with them.  Energy numbers are per pellet.  The more pellets, the more energy, and more chance to hit a "sweet spot". 

Reloader

Deformation plays no role in killing turkeys. We strive to do one thing, damage the CNS(break the skull or neck bone).  Density and hardness play a large role in breaking bone. Hevi will break bone much easier than lead, but that is not why it is a better shot for long range. It is a better shot plainly because it will place impacts on target when lead will not.

There's absolutely nothing in the world wrong with shooting lead shot at turkeys, but will someone please post a lead pattern that achieves over 100 hits in the 10 at 60+yds. Maybe we should rephrase that and say 50yds :D

I could use lead from now on with complete confidence. However, I'd have a 40-45yd confidence range depending on the gun.  I'll be danged if I'm going to have to pass up the rare bird that hangs at 50-60 when I'm on limited time.  I like to kill em at 30 as much as the next guy, but crap happens in the turkey woods.

Friday was a perfect example.  My cousin Heath had a nice tom at 55yds in a NE wind with no chance for a closer shot as the tom was leaving for hens.  He gave the bird 10" lead into the wind and absolutely devastated his noggin with a hevi 7 handload.  He has kill counts past 65yds with that particular setup, slash 10yds for the conditions, and he had a dead bird with a blood soaked head full of holes and a completely broken neck bone. I walk up to the bird and he said "I would have had to let him walk with lead shot" I said yep, sure would've.

Have a good one,

Reloader

jfair

#8
Quote from: new2turkey on April 20, 2011, 10:32:41 AM
Quote from: JUGHEAD on April 20, 2011, 10:28:52 AM
Another thing you didn't consider in your calculations is down range velocities and what the KE at those ranges will be.  A heavier projectile, with the same aero profile, will lose it's velocity at a slower rate down range due to higher momentum.  Number at the muzzle don't mean a whole lot.  Not trying to nit pick....just something else to ponder as you think through all of it....


Very true... Think about hitting a golf ball with a club, and then a ping pong ball.

You strike both at the same speed, and the ping pong ball slows right down, and curves all over the place...



Better patterns and holding velocity...

Maybe we could get a company to manufacture pellets with dimples like a golf ball.   ;D  Would decrease the drag and keep them flying straight.

Try that experiment again with a golf ball and a bowling ball.  Point being that the ratios are not in line.

jfair

I am in full agreement on Hevi being better than lead.  Pattern density being top of my list.  I can shoot 110's with lead and 180's with hevi, so hevi it is.   My feeling is if you are shooting an even pattern and keeping over 100 in the 10 inches then fire away at that range, lead or hevi.  Maybe not on this board but I know allot of guys who think this stuff is a killer load at 50, 60, 70 yards and never bother to see for themselves what the pattern is.  The talk is that hevi has that much more kinetic energy.  Simply saying "hevi does not have that much more kinetic energy, not according to the math".

drenalinld

IMO you don't want to push HS faster than the speed of sound. Projectiles with poor ballistic coefficients breaking the sound barrier can have erratic flight. I think EM purposely keeps it just under the speed of sound.

I may be way off, some of you guys may load HS with higher MV's with great results?

jfair

Quote from: drenalinld on April 20, 2011, 11:58:18 AM
IMO you don't want to push HS faster than the speed of sound. Projectiles with poor ballistic coefficients breaking the sound barrier can have erratic flight. I think EM purposely keeps it just under the speed of sound.

I may be way off, some of you guys may load HS with higher MV's with great results?

Right on with the ballistic coefficients.  Most competition air rifles shoot in the 600 fps range because of the accuracy tailing off at higher velocities.  They are punching paper and not turkeys though.  Got to find that point you cannot cross.

Reloader

1150-1350 is the sweet spot for hevi.  EM's low MV theory is bunk.

drenalinld

So I'm way off. I guess the SD of HS is high enough that the sound barrier has little effect on it.

jfair - i was thinking from an air rifle standpoint as well

reloader - I'm not sure if it is EM's theory or not, just my suggestion of a possibility for them keeping velocity down. I'm sure they are cutting costs.

Hay Flats

I would go with the increased pattern density of straight #7's, even at the lower velocity.  I've twice witnessed a low-flying #7 pellet completely penetrate the breast and end up under the skin on the OPPOSITE side of the bird...both times in the 35-40 yard range.  That's plenty of oomph!  ;)
[/quote]
That's amazing out of a #7 I have shot a bunch of birds with Hevi-13 5's & 6's and only the 5's have made it to the breast bone on any of the birds a few have broke through into the vitals but not many, I shot a nice bird the other day at 45 yards with Hevi-13 3" 2oz #6's and it stomped him but every body hit was just a little bruise, Broken feathers on the outside but a little purple bruise on the skin.

Kurt