Shooting under/over a Power Line-Check My Math

[varmint slayer]

Ok so here is the deal, I am wanting to setup a target at 2000 plus yards on my own personal range that is accessible by truck all year round. My current 2000 yard range is is down a two track dirt road with no gravel or anything so when it gets wet out or the spring snow is melting, I can't get in there with a pickup without tearing the road up. I can make it on my four wheeler but I really don't like doing that when I know I may have other options for a 2000+ yard range. I have the perfect area picked out but there is a power line that runs perpendicular to the line of sight to the target. The power line is 1370 yards from the firing position. By my math I think I should be able to shoot to 2000 yards plus and not have to worry about the bullet even coming all that close to the 3 phase power lines. Here is how I crunched the numbers. Let me know if you think this math is solid.

Firing position- 4830' ASL
Power Lines 4827' ASL with the bottom wires being 18ft above the ground for an elevation of 4843' ASL
Target-4877' ASL

Load data:

.338 LM
285 Hornady @ 2830 FPS
25.0 station pressure
58 degree temp


Max Ordinate of a 2000 Yard shot with that load would be 574.7 inches [MENTION=7008]117[/MENTION]0 yards
574.7/12=47.89' above the bore

Height of the bullet @ 1370 yards= 546.7" or 45.75' above the bore

45.75' (height of bullet @1370 yards) - 18' ( height of the power lines)= 27.75' above the lowest power line.

So by my math I should be well above the lowest power line and actually probably 20' above the highest power line so the power lines shouldn't be an issue if I use this range for 2000+ yard shooting. I understand that if I move the target in closer (and I dont know what range that would be without running some numbers), could result in coming really close to the power lines due to the change in trajectory. Any critique or help with my math is welcome and appreciated. Thanks

 

[BGE541]

Your math looks spot on but just like shooting over a road, if there is a slight chance I will find another way. Great looking layout though. Plan for the worst but hope for the best...

 

[jonaddis84]

I hate you, so I refuse to answer this question. I'd say go for it, and be sure to police your brass and wipe down your bullets after loading them.

 

[varmint slayer]

I hate you, so I refuse to answer this question. I'd say go for it, and be sure to police your brass and wipe down your bullets after loading them.

Would it make you feel better if I said you can try your luck at 2000+ on this very range in about 2 months?

 

[P7id10t]

Most excellent! Go for it, but don't fook up. At 18', what are you dealing with, 4.7, 7.2 or 14.4 KV power lines? Hitting one would make for awesome fireworks.

 

[peaceatwar]

Shameless "do it"

Just remember to back your truck in so you can high tail it if you need to.

 

[LRI]

You hit a wire and kill the power to my shop you can count on me flicking a booger at your windshield! A big one. I'll be sure to save one after sanding stocks just for you!

 

[varmint slayer]

You hit a wire and kill the power to my shop you can count on me flicking a booger at your windshield! A big one. I'll be sure to save one after sanding stocks just for you!

Haha well don't worry Chad, this line only feeds power to a bunch of old methane wells that are no longer active so the machines should be able to run full tilt if do take one down!

 

[jonaddis84]

Would it make you feel better if I said you can try your luck at 2000+ on this very range in about 2 months?

No, it doesnt. Because I wont hit anything with my pussy little 7mm now, and on top of that I will have to leave this range, its not in my backyard.

 

[varmint slayer]

No, it doesnt. Because I wont hit anything with my pussy little 7mm now, and on top of that I will have to leave this range, its not in my backyard.

We can move over to the 1 mile and under range so your 7mm can play too...

 

[P7id10t]

No, it doesnt. Because I wont hit anything with my pussy little 7mm now, and on top of that I will have to leave this range, its not in my backyard.

Your 7mm is fine. The pussies are the ones who don't shoot theirs because they kick too much.

 

[varmint slayer]

Most excellent! Go for it, but don't fook up. At 18', what are you dealing with, 4.7, 7.2 or 14.4 KV power lines? Hitting one would make for awesome fireworks.

The lines are probably somewhere in the 4.7 KV area and like I said they only feed some old methane wells. The line is still energized so that is why I am still a little reluctant to shoot over them with math not being solidified by a few different people on here. Would make me feel better if I had a few more opinions on this.

 

[varmint slayer]

Anybody else have any thoughts on my calculations? Would like some input from a few others that maybe have dealt with a similar situation. Not necessarily shooting over power lines but any situation where a shot had to be taken and there was something that had to be shot over or under.

 

[LWILLIAMS]

i do think this is a bad idea...only based on what has happened up my families farm in fresno, CA.

there are some 220 lines going across the field of trees of 20 acres about 200 yards out.
the target is for close up pistol shooting - 2 large wooden boxes filled with wood....

but with a 7.62, it penetartes the wood.
well, my cousin fored some shots from his AR and the wood was enough to deflect the bullet upward slighly and it did hit the power line causing it to break...
and the power line service our neighbor so they were without power.
it was one of those one in a million... but it did happen. so...................


[please beware that shit does happen - so just be VERY careful and anticipate the unexpected.

Trevor, If this were to happen I would just run like hell and say Cinch done it.

 

[varmint slayer]

Trevor, If this were to happen I would just run like hell and say Cinch done it.

HAHA [MENTION=8435]LWILLIAMS[/MENTION] I was already planning to blame [MENTION=17833]Cinch[/MENTION] !

 

[Cinch]

HAHA [MENTION=8435]LWILLIAMS[/MENTION] I was already planning to blame [MENTION=17833]Cinch[/MENTION] !

Oh you know damn good and well the I couldn't hit a power line at that range... Unless I was aiming at it...grin

 

[M-54]

If you had the "perfect range" it wouldn't have the power lines across it. If you were shooting bad guys your math looks good. If this is recreation you are too close. Run this by the power company first and let them know when you will be shooting, get a couple million in liability ins. and you have the perfect range. Presto

 

[40xs]

I retired from a power co. on the east coast and investigated suspicious outages. mathmatically and theoretically you alone may be ok in doing what you describe. However, you would not want to be a "person of interest" in the event that one of those lines fell. Depending on who the customers are that the line serves, there could be some hefty losses involved as a result of a power failure, with down time, loss of revenue, computers off line,etc. these can be very expensive. Even if you didn't cause it someone would know that you shoot there. Knowing the ramifications of such I'm not sure I would chance it. Something you have to decide.

 

[flounderv2]

Have you ever taken a shot at 1mile+ ? Do you think you will come within 15-20 ft elevation wise on your cold bore? Because if you are 15-30ft low on your POI, then your round may be a lot closer to those power lines than you think when passing over.

 

[rpk762]

If you do hit it just use the 5th amendment. If they are not being used the power company might be willing to remove the lines for you. It would be better to have a neighbor call for their land so if you do hit one they just do not come to you.

 

[40xs]

rpk762. WOW!! Really!! varmentslayer, if that ever happens let me know how that worked for you.

 

[TiroFijo]

If in doubt, there is no doubt... DON'T do it.

 

[varmint slayer]

Have you ever taken a shot at 1mile+ ? Do you think you will come within 15-20 ft elevation wise on your cold bore? Because if you are 15-30ft low on your POI, then your round may be a lot closer to those power lines than you think when passing over.

Yes I have taken quit a few shots at 1K plus and quite a few at 1 mile plus. I am pretty confident that my "cold bore" (or what I like to call cold shooter in most cases) will be within 15-30ft of the target. I keep a range card so my DOPE should be pretty darn close as far as elevation goes. The wind hold is what usually gets me but is still pretty much within a couple of MOA even on the windier days. For me to be 15-30 ft low at the power lines which are at 1370 yards, I would have to miss the target by more than 200 yards short. I'm pretty sure that my Terrapin and my shooting ability is a little better than that haha.

As for the rest of the comments as they are all leaning towards the don't do it answer, you guys are probably right on not attempting it and it being to much of a risk. I agree with you there and that's why I just wanted to see what others thought. I really wanted to see if I had crunched the numbers right more than anything. Like I said in the original post, I have another option for an all weather 2K plus layout. This location is just closer to the house and has the one road that runs parallel to the range for easy access. The other option is a lot farther around but has no power line issues so I'll probably be setting up on it instead of risking it. Thanks for everybody's input though.

 

[40xs]

One last note from me on this. I was observing a police officer prepping for an F-class match and he was on the 600 yd point. He had set his scope come ups for 600 and fired a couple rounds for affect but didn't get on target. His spotter couldn't pick up his miss. I got my binos and saw his third round hit in the ground around 300. I told him and after checking his scope again he realized he had only come up 16 "clicks" instead of 16 minutes. A BIG DIFFERENCE. We all have brain farts once in a while. If this happens to you on this piece of property, " WHOA BABY"!!! If you err, try to err on the side of caution, not chance.

 

[_Windrider_]

If it was a downhill shot, maybe. But this is pretty flat. It's tempting but maybe use this area for 1200 or less.

 

[SWRichmond]

I retired from a power co. on the east coast and investigated suspicious outages. mathmatically and theoretically you alone may be ok in doing what you describe. However, you would not want to be a "person of interest" in the event that one of those lines fell. Depending on who the customers are that the line serves, there could be some hefty losses involved as a result of a power failure, with down time, loss of revenue, computers off line,etc. these can be very expensive. Even if you didn't cause it someone would know that you shoot there. Knowing the ramifications of such I'm not sure I would chance it. Something you have to decide.

+1. There is a difference between "I think I can get away with shooting here" and "It is safe to shoot here". If you knock down someone's power line, be prepared to pay for their economic losses, however large they might be, plus the cost of repairing the line, which I am sure would shock you. Suppose you get out there, fire a round, and are able to observe no impact or trace. What will you do then? Shoot again?

 

[LWILLIAMS]

To hell with it Trevor, I will fling the first lead. Just get ready to run and claim you know who done it. We all need to get together and throw some lead once it warms up. Even though Gillette seems tropical compared to Williston here.

 

[varmint slayer]

[MENTION=8435]LWILLIAMS[/MENTION] Yeah we definitely need to do some shooting when it gets warmer. Get you and [MENTION=17833]Cinch[/MENTION] out here and pound some steel. I am going to buy some more steel so there is a plethora of targets to hit. Do our own little gentlemens bet type match sometime.

Hell maybe you could bring some survey equipment and we could get it down to the nats ass on the heights and distances of this power line and come up with a theoretical height above the lines the bullet would be, just to see how good my redneck estimates were.

 

[Prebanpaul]

I say please use the guys Idea with the tracer round, but I would like to add that you do this in lowlihgt and with a video camera. Either way I want to see this. Either powerline down, or one hella of a cool shot.

 

[K2Ballistics]

Uhh, I'm gonna say, whatever you do, DO NOT call the power company.

 

[Darkphage]

My 2 cents, probably not worth it. Odds are it'll never happen, but if it did it could make ALL your ELR gear seem like a couple bucks in comparison to damages you might be liable for.

Dark

 

[varmint slayer]

Yeah I don't think I will be attempting this any time soon. I do like the tracer round idea though...

Too much risk and like I said above, I have an alternate layout for 2K plus with no obstacles to shoot over/under or around.

 

[rpk762]

More than one area to go that far? Nice. I guess now would be the time to call the power company and start complaing for them to move those lines. Then you will have more than one area you can really shoot that far.

 

[varmint slayer]

More than one area to go that far? Nice. I guess now would be the time to call the power company and start complaing for them to move those lines. Then you will have more than one area you can really shoot that far.

I actually have more than 2 places but and actually a few more places that are accessible all year round but they are a little farther from the house than the others. When I say farther away I mean like 10 min vs 5 min but I really want the closer ones lol.

Hopefully in the next few years they will be taking that power line down as there will be no need for it once all the wells are gone. Hell all that power line has done in the last 2 years is spark and burn up 1000 acres of grass lol.

 

[InsidetheStorm]

Well, if you were trying to hit the lines, Murphy says you couldnt do it with a million rounds, unless you were trying NOT to hit the lines. Then, it's a first round go.

 

[varmint slayer]

Well, if you were trying to hit the lines, Murphy says you couldnt do it with a million rounds, unless you were trying NOT to hit the lines. Then, it's a first round go.

That's no shit....lol

 

[Quark]

I'm curious ... how did you determine the voltage and height of the line ? anything over 220V wouldn't be at 18 feet would it ? 18 feet is usually the height of telephone cabling. AC is above that. And HVAC is usually much higher. And then there is how are you going to allow for cable droop/sag ?

This has Darwin Award written all over it.

quark

 

[varmint slayer]

I'm curious ... how did you determine the voltage and height of the line ? anything over 220V wouldn't be at 18 feet would it ? 18 feet is usually the height of telephone cabling. AC is above that. And HVAC is usually much higher. And then there is how are you going to allow for cable droop/sag ?

This has Darwin Award written all over it.

quark

The voltage is actually 14.4K per phase after talking with a friend that is line man that works at the power company. The height was determined by using my Terrapin set to feet and ranging the cross bar where the line is secured to. Also confirmed the usual instalation height of the poles/wires with him. Believe it or not 14.4k volts is considered medium voltage in the power line business but that doesn't make it any less dangerous. There is no need to account for line droop as the shot would be going over the lines at the pole I measured. Sure wind is going to alter the point where the bullet is going pass over the pole but not enough to worry about it.

Also this wouldn't qualify for a Darwin Award as more than likely death would not be the end result of hitting the line and being 1370 yards away...

 

[Quark]

I was being facetious about the Darwin Award. So I apologize about that. But from what I know about this from having worked for a Public Utility is that there are standards for the heights of these things. Now I freely admit that these "standards" may very well not apply to very rural areas but nonetheless are a reasonable starting point.

Bottom Line: I wouldn't do it. I'm not very smart but this one doesn't pass my judgment test. Your mileage may vary.

 

[varmint slayer]

I was being facetious about the Darwin Award. So I apologize about that. But from what I know about this from having worked for a Public Utility is that there are standards for the heights of these things. Now I freely admit that these "standards" may very well not apply to very rural areas but nonetheless are a reasonable starting point.

Bottom Line: I wouldn't do it. I'm not very smart but this one doesn't pass my judgment test. Your mileage may vary.

I hear ya man. Like I stated earlier in the thread, I will more than likely not be trying this as I have other options for 2K+ yards. This spot is just basically in my front yard and the other spots are a few minutes drive so not a big deal.

 

[softcock]

Shooting Long Range over & under high tension power lines .. No Sweat . But I would fear that the electromagnetic field of flux given by the power lines would throw-off my precision ballistic calculations I made on the Coriolis effect with my bullets flight to target .
.

 

[McCrazy]

Firing position- 4830' ASL
Power Lines 4827' ASL with the bottom wires being 18ft above the ground for an elevation of 4843' ASL
Target-4877' ASL

Max Ordinate of a 2000 Yard shot with that load would be 574.7 inches @ 1170 yards
574.7/12=47.89' above the bore

Height of the bullet @ 1370 yards= 546.7" or 45.75' above the bore

45.75' (height of bullet @1370 yards) - 18' ( height of the power lines)= 27.75' above the lowest power line.

So by my math I should be well above the lowest power line and actually probably 20' above the highest power line so the power lines shouldn't be an issue if I use this range for 2000+ yard shooting. I understand that if I move the target in closer (and I dont know what range that would be without running some numbers), could result in coming really close to the power lines due to the change in trajectory. Any critique or help with my math is welcome and appreciated. Thanks
View attachment 2188

The first thing that stands out to me is that someone who thinks that 4827+18=4843 should absolutely not trust his math skills.

Second is that if you are shooting at a target 47' above your firing position and there is an obstacle 2/3 the way to the target which is 15' (after fixing the addition error) above the elevation of the firing position that even a laser (or your line of sight) should be above the obstacle, and the actual trajectory of the bullet significantly higher than that.

So we can see you should clear the lowest power line but you have no numbers for the height of the highest power line which is the real concern. I guess you were worried about the lowest line which raises more questions in my mind. Such as: did you think you were going to shoot under the power lines? If so, refer to the lines of thought above and below this sub-paragraph.

If from your firing position the lowest power line appears to be above your line of sight (not line of bore as you refer to) then your altitude measurements are probably off and need to be resolved and all your calculations redone.

***I am not trying to belittle anyone so if my tone sounds like that it is not my intent. If we are going to take large risks like this we need to make sure our measurements, calculations, and conceptual understanding is clear and correct. Doesn't quite seem to me that those bases were covered initially.

 

[varmint slayer]

The first thing that stands out to me is that someone who thinks that 4827+18=4843 should absolutely not trust his math skills.

Second is that if you are shooting at a target 47' above your firing position and there is an obstacle 2/3 the way to the target which is 15' (after fixing the addition error) above the elevation of the firing position that even a laser (or your line of sight) should be above the obstacle, and the actual trajectory of the bullet significantly higher than that.

So we can see you should clear the lowest power line but you have no numbers for the height of the highest power line which is the real concern. I guess you were worried about the lowest line which raises more questions in my mind. Such as: did you think you were going to shoot under the power lines? If so, refer to the lines of thought above and below this sub-paragraph.

If from your firing position the lowest power line appears to be above your line of sight (not line of bore as you refer to) then your altitude measurements are probably off and need to be resolved and all your calculations redone.

***I am not trying to belittle anyone so if my tone sounds like that it is not my intent. If we are going to take large risks like this we need to make sure our measurements, calculations, and conceptual understanding is clear and correct. Doesn't quite seem to me that those bases were covered initially.

Ok you got me on the math, It was a typo I'm thinking. 4827+18=2845. I am guilty of only going out and getting elevations and rages to try to do the calculation so I have not actually gone out and checked to see what it actually looks like lined up behind the gun. Your thought process is exactly the feed back I was looking for and has sparked my interest in this again towards the possibility of this being doable in theory. I will double check my numbers to verify the data is all correct so that we can say the calculation is as close as it can be.

As far as the over/under part goes, I was pretty certain that with a 2K yard shot that the bullet would be over the lines but just not sure by how much. I was/am pretty confident in the way the calculation was done, maybe just not the data now that you pointed it out.

The bottom wire(s) are indeed 18ft (if my data is correct lol) and the top wire is maybe 2-3 ft about that and that is a guess at this point but its not much more above it so I don't think that it will make much of a difference for me. If it looks like I will be coming within 15-20 ft, its too close for me.

 

[McCrazy]

Sounds good. Glad that this renews your interest in checking this out rather than giving up.

Best of luck to you.

And the power lines.

 

[Christopher Rance]

Obstacle Clearance. With known set of scope data and/or Mil holds, we can easily compute the bullets location at any point during its flight to include potential clearance under/over obstacles.

We are concerned with the following variables.
a. Range to obstacle with associated hold/scope data.
b. Range to target with associated hold/scope data.

Clearance required (CR) = Target data/hold - Obstacle data/hold

CR tells you your bullets location at the obstacle within in the optic, therefore you must calculate CR in Mils.

Example:
Obstacle = 300 meters / 1.56 Mil
Target = 550 meters / 4.76 Mil

CR = 3.2 Mils

 

[DoctorBen]

I do love a good ballistic problem. I think you'd be clear of the lines, but I'd be a little too worried about being wrong to pull the trigger, especially when in the time it takes me to unpack, I can be at a range without obstruction.