THEORY: Danger space vs caliber

[turnburglar]

Hey guys I was up late worrying about this ballistic problem.

If caliber A exhibits B amount of drop at C range making the danger space 1/1 ratio, does increasing A increase C if we wish to maintain that 1/1 ratio?


KISS: does margin of error increase doing range E with a reticle by shooting a flatter bullet?

[taliv]

huh ?

[militarymoron]

why don't you draw a graph with the trajectory and danger space/fields for the first example to help us visualize what you're referring to? when you say 'increase A', that doesn't mean much other than increasing the diameter of the caliber. what's changed in the trajectory?

[mark5pt56]

I think he may be asking if he jumps up in caliber, will he increase his danger space. Well that will depend on the load in that caliber and is that larger caliber more efficient. You have to give us more precise information on the current and desired load and or caliber, exact bullet, velocity and of course the ending density altitude which will have to be the same when you compare.

And yes, if the bullet is dropping less in x distance, range estimating error is more forgiving to a certain extent.

And I'm guessing on what you are asking.

You can go to JBM ballastics or if you have Nightforce's program or even Applied Ballistics, etc. input data and you should see the results

[C-grunt]

What is "danger space"?

[mark5pt56]

You have point blank range and danger space, kind of the same in definition. I see the shorter range more so for a hunter(short range hunter) and the danger space more so for the long range hunter and target shooter("target" being a relative term)
Point blank range theory that you sight in at a certain distance so you can hit a certain size target within a range window--without adjusting your sights. You have to decide on that one as your needs may be different.

Danger space for long range gives you a window as well, but you would have to adjust your sights to get to the "new" window. Obviously target size, trajectory and range estimation come in to play, same as PBR. Of course range estimation is a moot point for KD ranges.
To qoute Bryan Litz "Danger space is the true measure of merit for a trajectory"
I will use the example from page 44 of his book using "a high BC .30 caliber bullet at a moderate muzzle velocity and a 10" target at 600 yards" "The bullet "occupies" the height of the target from 579 to 620 yards, meaning the 10" target is in the danger space of the trajectory for 41 yards".
Example, let's say your target is 10" and you range it at what you think is 600 yards and it's actually at 560, you will be low, off the 10" target
This is one of the reasons you see folks using the more efficient calibers for long range shooting. By having a better trajectory at the longer ranges, they are less susceptible to ranging errors for one because they extended the danger space.
Unless you have to deliver a payload onto target, the 6 and 6.5 mm calibers are clearly out performing the .308 and will match or exceed the 300wm in the trajectory. And after shoulder surgery, a 6.5 is a no brainer in place of a 300wm.

Taking it deeper you can clearly see where the long range shooter can extend his danger space by having an efficient caliber. In theory, he/she could also engage multiple targets without sight adjustment (after the initial adjustment for that particular range) or even minimal holds if those ranged targets are within the danger space of the cartridge utilized.

Found these as a supplement

http://en.wikipedia.org/wiki/Point-blank_range

http://www.figure14.com/#/blog/45694...-Space/3909840

from above
So what does all this mean? Well, if you only shoot at known distance targets, not much to be honest, but if your shooting entails engaging targets that are at unknown or uncertain distances, then knowing the Danger Space of the trajectory of the round you’re shooting could make all the difference.

[militarymoron]

In other words (as i understand it), if you had a laser gun, the danger space would be infinite (or the effective range of the laser), as the laser has no trajectory (it's flat).

[mark5pt56]

In other words (as i understand it), if you had a laser gun, the danger space would be infinite (or the effective range of the laser), as the laser has no trajectory (it's flat).

Correct, hence how some refer to their rifles as "lasers" which isn't quite correct.

[MBtech]

So this was used to calculate height of a calvaryman or infantry man on the field wether they would be in danger of being hit?

https://books.google.com/books?id=sl...ed=0CCcQ6AEwAw

[turnburglar]

Hey guys thanks for the replies.

I did more searching after I made the initial post and it appears a flatter cartridge is more forgiving.

I'm considering buying a bolt gun and am trying to figure out what would suit me best. It appears that you can only shoot as far as you can accurately judge distance.

Right now I am trying to decide if 7mm rem mag is worth the squeeze over 7-08. At the moment I don't intend on getting a laser and plan on doing range estimation with mil dots, so the more forgiving cartridge appears attractive.