by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- When the target is close, things change
- Not about the snake
- Trajectory — part one
- What it looks like to you
- Relationship of the sights to the bore
- Sight-in at 10-12 feet
- How I sight in a scope
- Remember the snake
- Different ammo
- Discount store pellets
- The deal
- New pellets
- Fishing sinker larvae
- How much influence is the pellet?
Before we start let me tell you that I wanted to finish my report on the IZH MP532 rear sights today. The reason I didn’t is because as time passes I learn more and more about them. I want to make certain that I have explored everything I can when I write that report. It will also have at least one video.
For today I thought I would return to this subject that many readers seem to enjoy. Please understand that B.B. Pelletier isn’t the world’s authority on shooting. I do know some things, though, and I enjoy writing about them. If what I know can help anybody, then I have done my job.
When the target is close, things change
Let’s start with a fact that seems to escape people until it’s too late. You sight in your deer rifle for 100 yards, knowing that you will probably encounter a deer anywhere from 50 to 125 yards where you hunt. If it’s greater than 125 yards you probably won’t take the shot.
Then, while you are walking to where the hunt starts, you encounter a copperhead snake on the trail. He is 15 feet away and he must be cold because copperheads are aggressive and they are known to attack, similar to water moccasins, though not quite as aggressive.
All you have is your deer rifle. You can barely see the snake through your 6-power scope. So — where do you aim? You don’t have a backup gun (put that on the list), so it’s either the deer rifle you’re carrying or time to start backing up. The trail you are on is cut into the side of a steep hill and it’s 3 feet wide. Kill the copperhead or go back!
Not about the snake
This is not about the snake. This is about suddenly realizing that all your planning for this hunt while you were sitting in your comfy recliner at home has not prepared you for a shot like this. You are prepared for shooting at 50 to 125 yards. Where will your bullet be at 15 feet from the muzzle?
Now, there is a secret to successfully shooting snakes, and for an extra 10 percent (each) over what you normally pay me, I will divulge it. But it’s not why we’re here. We are talking about the basics of shooting and this brings us to our first teaching point. Bullets and pellets do not travel in a straight line. The instant they emerge from the barrel, gravity starts to act on them and they fall to the ground just as fast as if you dropped them from your hand — assuming the barrel is level and the muzzle and hand are at the same height.
Trajectory — part one
You adjust the open sights or the scope to look DOWN through the trajectory of the falling pellet as it travels downrange. The adjustments are subtle, but I will exaggerate them to illustrate. And, from this point on I will be talking about a scope.
This is what happens with your pellet gun and sights. The down angles are exaggerated to fit on this page.
In the drawing above the scope is adjusted to just touch the pellet at one place in its trajectory. The rifle would then be sighted in for that one distance. Notice that the line of sight and the trajectory stay together for some distance. You are actually sighted-in for all those distances. But that might only be 5-10 feet, because as the pellet falls it also gains speed. The downward curve gets steeper.
What it looks like to you
The drawing above is correct, but we don’t see it that way. When we hold the rifle and sight through the scope it looks like this.
We hold the rifle level, so the line of sight both appears and actually is level. The trajectory, which we know is always falling down from the muzzle now looks like this.
Drawing number two is the reason why some people think that a bullet or pellet rises after it leaves the muzzle. The truth is — the angle of the scope only makes it look that way.
Relationship of the sights to the bore
The sights are mounted above the axis of the bore. In the case of a scope, they are probably 1.5 inches or more above the center of the bore. If you were to touch a paper target with the muzzle of your rifle and shoot, and if you could look through the scope and see the same target paper, the difference between where you were looking and where the pellet hit the paper would be the same distance that the scope is above the bore.
Sight-in at 10-12 feet
This is why I begun sighting in my scopes in at 12 feet. I would do it at 10 feet, but the door jamb I use to steady the rifle is 12 feet from my pellet trap. Over such a short distance I don’t expect the pellet to “rise” very much. If the center of the scope is 2.2 inches above the center of the bore I expect the pellet to hit the target about 2.2-inches below the aim point. If it does and if the pellet is pretty close to the centerline left and right, I feel confident to back up to 10 meters (11 yards or about 33 feet).
If the scope is sighted to angle down correctly, I expect the pellet to strike the target about one inch below the aim point when I shoot at 10 meters. If it does, or after I adjust the scope I can get it to that point, I know I can back up to 25 yards and the pellet will be pretty close to right on target. Now let’s see why.
How I sight in a scope
For an air rifle shooting a pellet of any caliber at 825 f.p.s. (which is slightly over 12 foot-pounds for an 8-grain .177-caliber pellet) I sight in for 20 yards. You may have read about the first and second impact points. I will explain them now. First, look at the drawing.
In this drawing we have zoomed in for more detail. The line of sight has been adjusted to pass through the trajectory at 20 yards, meaning it is sighted-in at that distance. Then, as the pellet goes farther, it appears to rise just a bit above the line of sight. Then, at around 28 to 30 yards, the trajectory brings it back down to the line of sight again.