Sniper's Hide Bullet Point - Danger Space
You see a lot of bad stuff on Facebook. This week we were treated to an image that supposedly showed a Paint Can that was hit by a 308 at 500 yards. The bullet entered the top, and was coming down at such a steep angle it exited near the bottom. It was near a 45 degree drop from the sky. The caption on the image was to demonstrate "Danger Space". For the precision rifle shooter Danger Space is defined as the area plus or minus the aiming point where the shooter will still hit a specific sized target. A great example of this is an Unknown Distance Target. Back when we used to reticle range, you had an error factor and the Danger Space would be given to you in yards. If you were off +/- "X" number of yards you could still reasonably hit the target. When we look at the competition shooter today, most of them are shooting fast, flat trajectories which, under time constraints can take up the error induced from the position or speed to still hit the target. When you have a heavy 6.5 bullet going 3150fps you have a lot of Danger Space and it allows them to hit the target with very little offset.
For the hunter the Danger Space can be the difference between a clean kill and a miss or worse, a wound. Today many of us use Laser Rangerfinders so the error factor has been reduced, however if you shoot to ELR Distances, it becomes an important factor to fine tuning your DOPE on a target that is beyond the Transonic Region. A few clicks plus or minus can be the difference between a hit and a miss on a very thin plate. It's much more critical at ELR Distances.
Tools of the Trade
For this lesson we used 3 different rifles,
Accuracy International AX308 with 20" Barrel
Ashbury Precision Ordnance ASW300
Cadex Defence CDX-33 338LM
First we shot them at 600 yards intersecting a target 5 yards in front of a second target. The Facebook image was supposedly shot at 500 yards, so we moved to 600 yards to show the actual bullet drop. Gravity dictates the bullet is falling as it leaves the barrel. We dial the scopes elevation up, the reticle goes down, which forces us to pick our barrels up and the bullet is meant to intersect the target at a given range based on the trajectory. Thanks to Danger Space, that range is not exactly fixed. We have a "plus or minus" distance where the bullet can still hit the target. See below
Danger Space happens more so on the backside of the trajectory, after the bullet as passed its Max Ordinate. While there is a still a Danger Space aspect up close, it's pretty wide and is more so effected by target size combined with distance. Yes the 300WM is a flatter shooting caliber than the 308, so it will require less elevation to hit a specific target over the 308.
What I have done here is copy the JBM Ballistic Information for all three rifles and bullets used, as well as conditions they were shot under. The information in the charts is accurate. I have included the Danger Space information as provided by JBM so you can see the error factor in ranges. This is shown plus or minus so many yards.... Yards, not inches.
Accuracy International AX308
Ashbury Precision Ordnance ASW300
Cadex Defence CDX-33
What You Don't See
Also shot, but not included in this video, a portion that will be saved for the Sniper's Hide Premium Members is the shots taken at 800 yards. I lined up two targets, 10 yards apart. The back target is an 18x24" plate and in front is a 12" plate that is in direct line with the other. So we have one target at 790, and the other at 800 with all the rifles doped for 800 yards. This way you can see what happens, and how Danger Space is governed by the trajectory. When the Danger Space is smaller the shot will go over the first target and just hit the back. When the Danger Space is larger you hit the first target.
What is a critical factor here, well the wind. But check out the charts and you can see what the results were.
Analyze the Data for yourself and look at the Danger Space. It's something use, even in competition. It's worth noting what options you have.
If you want more details, consider a Sniper's Hide Premium Membership as I will have a expanded view of this lesson with more video, and greater details as the effort put into this. It is about the angle the bullet is falling in many ways, but it's not something you can demonstrate correctly with a Paint Can.