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Terminal Energy Calculator Req'd

10K views 23 replies 11 participants last post by  huntingsgr8 
#1 ·
I am after a ballistics program that helps to work out how much speed and energy is left in a shotgun pellet downrange for different sizes and muzzle velocities.

If anyone could help please {hs#
 
#2 ·
#3 ·
That's a good table for target shot.

Some of the other stuff, not so hot. The choke data is OK, but only for a 12ga. The table in the lower right corner is really suspect....you can't compute recoil energy without taking into account the shot velocity, which isn't listed. To get 12.5 ft/lbs in a 8.4 lb 12ga the 1 1/8 ounce load has to have a muzzle velocity of only 1,000 fps. And who would shoot a 3.5" shell with 2.25 ounces of shot through a 6.5 lb gun??

If you can be more specific....#6 shot? #5? at 40, 50, 60 yds? I have some tables I can dig out of my files.

The only programs I can link you to are for recoil energy.
 
#4 ·
Gee, it's really unfortunate that the tables I posted a link to don't meet up with your standards, Mike. But after all, I didn't write the tables. I just posted a link to what someone else wrote...... even though it won't answer ALL questions that someone may ask and even though a few of the numbers on recoil (which wasn't even asked about) are a bit suspect.

Perhaps after you locate your 100% complete and 100% accurate tables you'll be kind enough to post them for everyone.
 
#5 ·
Ulysses said:
Gee, it's really unfortunate that the tables I posted a link to don't meet up with your standards, Mike. But after all, I didn't write the tables. I just posted a link to what someone else wrote...... even though it won't answer ALL questions that someone may ask and even though a few of the numbers on recoil (which wasn't even asked about) are a bit suspect.

Perhaps after you locate your 100% complete and 100% accurate tables you'll be kind enough to post them for everyone.
I very much appreciate your contribution to this topic , but I must admit I am hoping to find something that allows me to enter my own values, bigger slower shot etc.

Nevertheless thanks for the link {hs#
 
#6 ·
You're welcome. Sorry that it wasn't exactly what you were looking for, but I'll bet that you could do some extrapolating and estimating from the data given and come pretty close. Good luck.

If you have a few specific numbers or values you would like, post the criteria and let's see what someone could come up with.
 
#7 ·
Ulysses said:
You're welcome. Sorry that it wasn't exactly what you were looking for, but I'll bet that you could do some extrapolating and estimating from the data given and come pretty close. Good luck.

If you have a few specific numbers or values you would like, post the criteria and let's see what someone could come up with.
My thoughts are in relation to some low velocity loads I make for moderated shotguns (legal over here). They are 1080 FPS muzzle velocity and in a 28 gram load only appear to be equal to maybe a 21gram standard velocity load of say 1300FPS if you compare the kinetic energy of the whole payload as one lump.

Going up a shot size and a choke size seems to give them a fair killing range per pellet but I wanted to crunch the numbers for maybe 5s and 6s down range.
 
#8 ·
How about this.

If a 7.5 (English) @ 1300fps has a muzzle energy of 4.7ft lb and a no6 @ 1080fps has a ME of 5ft lb, how do they compare at say 35- 40 yards?

That's the kind of thing I am trying to find out, will the slower heavier pellet hold its energy significantly better etc.
 
#9 ·
I'm betting that the bigger pellet still has higher energy at the full range, and the difference gets greater as you increase distance. Especially since it starts out higher M.E.
 
#10 ·
Why? Shotguns kill from multiple hits not single pellets. That's why choke is important. Pattern density runs out before pellet energy goes below some unspecified unacceptable level. If one pellet was all it took, everyone would be shooting straight cylinder or even spreader loads at max range.
 
#12 ·
sitsinhedges said:
How about this.

If a 7.5 (English) @ 1300fps has a muzzle energy of 4.7ft lb and a no6 @ 1080fps has a ME of 5ft lb, how do they compare at say 35- 40 yards?

That's the kind of thing I am trying to find out, will the slower heavier pellet hold its energy significantly better etc.
Hawglips has an excellent program that shows the penetration of various sized pellets and pellets made from various materials. I know it includes muzzle velocity and downrange velocity and possibly the energy too. I sent him a message and I hope he can post on this subject.
 
#13 ·
sitsinhedges said:
How about this.

If a 7.5 (English) @ 1300fps has a muzzle energy of 4.7ft lb and a no6 @ 1080fps has a ME of 5ft lb, how do they compare at say 35- 40 yards?
In this example, at 35 to 40 yards (or ANY distance for that matter), the #6 will have more energy than the #7.5 pellet. This is due to two main factors. First, the heavier pellet will hold its velocity better at distance than a lighter pellet. Second, the faster any pellet leaves the muzzle, the faster it slows down. So I would expect the difference in energy between the 2 pellets to be even greater (percentagewise) at 35 to 40 yards than it is at the muzzle.

As for actual numbers, I expect the #7.5 to have about 1.4 ft-lb energy at 35-40 yards, and I expect the #6 pellet to have about 1.7 to 1.8 ft-lb energy at that same distance.


That's the kind of thing I am trying to find out, will the slower heavier pellet hold its energy significantly better etc
Absolutely!
 
#14 ·
Ulysses said:
Quote:
That's the kind of thing I am trying to find out, will the slower heavier pellet hold its energy significantly better etc
Not because it is slower, but because it is heavier and has more energy to begin with, and will loose the energy at a slower rate due to the increased weight.
 
#15 ·
sitsinhedges said:
How about this.

If a 7.5 (English) @ 1300fps has a muzzle energy of 4.7ft lb and a no6 @ 1080fps has a ME of 5ft lb, how do they compare at say 35- 40 yards?

That's the kind of thing I am trying to find out, will the slower heavier pellet hold its energy significantly better etc.
I think what you need is Shotshell Ballistics for Windows created by Ed Lowry and Keith Garner, but apparently it is not available retail anymore.

There's some relevant discussion here if you want to wade through it.

http://www.duckhuntingchat.com/shotgun- ... istics.php

This is not exactly what you're looking for but I find it useful because I only hunt upland birds and do like a standard velocity for my hunting loads.

 
#17 ·
Sitsinhedges, sounds like you'd like the KPY Shotshell Ballistics Program. It's got all of what you are looking for. You just plug in the type shot, speed, payload, etc, and you get all kinds of good stuff back.

http://shotshellballistic.blogspot.com/

As for actual numbers, I expect the #7.5 to have about 1.4 ft-lb energy at 35-40 yards, and I expect the #6 pellet to have about 1.7 to 1.8 ft-lb energy at that same distance.
Comparing lead 7.5s at 1300 fps MV with lead 6s at 1080 fps MV, you get the following 40 yard results (at 5000 ft alt and 32 deg. F):

#7.5s...energy 1.31 ft lbs....Energy Density 184.9....ballistics gel penetration 1.36"....final velocity 684 fps
#6s......energy 1.91 ft lbs....Energy Density 200.7....ballistics gel penetration 1.61"....final velocity 663 fps

Not because it is slower, but because it is heavier and has more energy to begin with, and will loose the energy at a slower rate due to the increased weight.
And just to show how pellet density trumps pellet size, pellet weight, or pellet (MV) speed --comparing the #6s to an even slower (1000 fps), lighter, but more dense 18g/cc pellet you get the following:

TSS #8s...energy 1.94 ft lbs....ED 304.7...ballistics gel penetration 2.55"...final velocity 709 fps
 
#18 ·
Here's another comparison at 40 yds, showing how more energy doesn't necessarily mean better penetration:

Steel #2, 1500 fps MV
energy 4.77 ft lbs....ED 269.9...ballistics gel penetration 1.92"...final velocity 782 fps

Hevishot Goose #6, 1250 fps MV
energy 2.59 ft lbs....ED 272.7...ballistics gel penetration 2.08"...final velocity 743 fps

TSS #9, 1240 fps MV
energy 1.59 ft lbs....ED 315.9...ballistics gel penetration 2.42"...final velocity 766 fps
 
#20 ·
hawglips said:
Here's another comparison at 40 yds, showing how more energy doesn't necessarily mean better penetration:

Steel #2, 1500 fps MV
energy 4.77 ft lbs....ED 269.9...ballistics gel penetration 1.92"...final velocity 782 fps

Hevishot Goose #6, 1250 fps MV
energy 2.59 ft lbs....ED 272.7...ballistics gel penetration 2.08"...final velocity 743 fps

TSS #9, 1240 fps MV
energy 1.59 ft lbs....ED 315.9...ballistics gel penetration 2.42"...final velocity 766 fps
Atta Boy!
 
#21 ·
Here's an interesting look at the distance different size/type pellets will penetrate ballistics gelatin to the depth of 2 inches:

At 1300 fps MV, penetration in ballistics gelatin to depth of 2 inches

Steel #4......................14.2 yds
Steel #2......................27.7 yds
Steel #1......................35 yds
Steel #BB....................50.5 yds

Lead #8......................12.4 yds
Lead #6......................31.5 yds
Lead #5......................42.2 yds
Lead #4......................53.4 yds
Lead #2......................77.6 yds

Hevi #7.5....................24.2 yds
Hevi #6......................41 yds
Hevi #4......................65.9 yds

Fed heavyweight #7.....59.4 yds
Fed heavyweight #6.....75.9 yds

TSS #9......................53.1 yds
TSS #8......................72.6 yds
TSS #7......................93.4 yds
TSS #5.....................138.4 yds
 
#22 ·
Hawglips - The velocities your program is showing match pretty closely with what the program I use shows, although my program is considerablymore cumbersome. What doesn't even come close is the Ballistic Gelatin penetration (done with a seperate program). The one I use matches pretty closely with actual tests that I have found, but most of those tests have been with Buckshot. I can't seem to find any that show small pellet penetration. (The program I use shows deeper penetration).

DC
 
#23 ·
Since I don't really know what penetration depth is required for "X" or "Y" game, to me, the primary value of the penetration depth is for an apples to apples comparions of different shot sizes and types. Relativity, not absolute numbers, is what interests me with it. So, it doesn't matter to me whether a program shows more or less absolute depth, as long as they are consistent with comparisons.

I found in my own rudimentary sheet metal tests, that the relative penetration reflects what the program shows -- with the exception of lead. Lead penetrated the sheet metal much more poorly compared to the harder, denser shot. I figure that is most likely attributable to the softness of lead. But I also see value in knowing that, since all game has soft tissue AND hard bone....
 
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