Question range finding with mil dots

[PAUL1986]

great video, I just need to convert meters to yards and I'm all set to start calibrating.

[nick2]

then you'll need to buy a range finder- more expense

[PAUL1986]

as if

[Jay Jay]

CORRECT! This is because the pellet does not go straight, it flies in an arc through the air. As soon as the pellet (or a bullet) leaves the muzzle it is acted on by gravity, pulling it down off the straight flight. The further it goes, the more it drops, just like a stone when you throw it. If the barrel is parallel to the flat ground, the arc starts as soon as it leaves the muzzle and gets progressively steeper the further the pellet flies. To combat this, we set our guns (air rifles or rifles) up so that the muzzle is NOT pointing straight at the target, but slightly up. (If you want to throw a stone a long way you aim up in the air a bit to give it more time to defeat gravity). The amount you lift the muzzle (called elevation) depends on the distance you want to shoot. 30 yards the elevation is barely descernable, but it is there just the same. If you want to shoot 200 yards you have to aim at the top of the trees!
Now, if you draw a picture (I can't, not even matchstick men!) of your rifle with the sight looking STRAIGHT at the target (the line of sight IS straight because light travels in straight lines as it is NOT affected by gravity) your sight is looking straight at the target, the rifle is pointing SLIGHTLY up.

The scope is also slightly HIGHER than the barrel (it has to be, it sits on top of it!) so to start with, the line of sight is ABOVE the line of flight. That means the pellet is below the line of sight (so it will hit low). There is a small triangle between the muzzle of the gun and the line of sight until the two paths cross. This first point of the pellet crossing the line of sight (at somethng like 10 or 12 yards) ON THE WAY UP is your primarary zero distance. You can aim dead on and the pellet will hit where you aim. Past this point the pellet continues to rise on its arc, so it is now travelling ABOVE the line of sight and you will hit high by however much according to the distance (range) from the muzzle. At the highest point of the flight arc (the zenith of the arc) the pellet (or bullet of a rifle) starts to fall back to earth again and the arc of flight starts to curve downwards, getting ever steeper in curve the further it goes.

At some point along the arc of flight, on its downward section, the pellet will again cross the line of sight. This is your secondary zero and it will be somewhere around the 30 yard mark (28 yards? 33 yards? 35 yards? depends entirely on speed of flight and pellet weight and the angle of elevation). Once past this point where it crosses the line of sight the pellet is then always falling further from the line of sight and so hits lower and lower the further out it goes.

You can CHOOSE the arc of flight by altering the elevation angle of the rifle. You do this by changing the line of sight in the scope - When you lift the point of impact by turning the knob/dial on the scope, in effect you are dialling in a minute amount of elevation of the muzzle. It is done optically and you are actually lowering the cross hair in the scope. With an artillery gun, you see them turning the wheel to screw the barrel up - with your air rifle you are doing the same thing, but in such a minute amount you can't see it.

Intersting point. If you have two identical guns strapped side by side, both pointing absolutely horizontal over flat ground (both same height), one fires a pellet at 750 feet per second, the other fires its pellet at 3000 feet per second. If you fire both guns at the same time the two pellets will hit the ground AT THE SAME TIME, it is just one will be further out than the other. This is because gravity is the same on both pellets and they both have the same distance to fall to the ground.

Hope that helps you understand what is actually going on in the air in front of you, when you fire your air rifle. The ACTUAL amount of rise and fall of the pellet will depend on : its weight, its velocity, the range and the amount of elevation you give it. The height of the sight above the barrel affects the triangle between muzzle and first crossing point.

Enough for now, or you will have information overload.

well done mate for that totally spot on and very well explained. You should do a guide on here very well explained even I understood!! Lol Top man


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