sighting in your rifle?

And I don't feel that I have a "poor" understanding of ballistics just a different idea to try at the range. And was trying to get everyones thought on the idea.
 
MPBR is an extremely common way to sight in a rifle, which is why it's included in so many (most?) ballistics calculators.
 
So, would you say that is where a bullet is most likely to perform its' best accuracy? Or is that only a concern as the bullet starts to slow its spin, and unwind (the best I can describe it)? Because my 22lr will put all 5 in one hold at 25 yards, but getting it to hit a paper plate at 100 yards, 7 times in 10 shots is about the best I can do.
 
My advice is to visit www.norma.cc if you find your way the the english version (british flag link)and click on "ballistic" you will eventually make your way to a trajectory program....enter the load properties, and you can play with the "zero range" and see the different paths the bullet will make.....give it a try, it's pretty helpful
 
A rifle will shoot most accurately at any range if it's zeroed in for that exact range.

Since game very seldom cooperates in only giving us a shot at that exact zero range, your choice is to either hold over (or under) to compensate for the difference between your zero and the (guessed at) actual range, adjust your scope/sights to that range, or to pick a MPBR where you will hit within a specified sized kill zone from the muzzle out to a relatively long range.

For instance if you designate an 6" kill zone in the calculator, depending on the exact range, you may be 3" low or 3" high, but at anything less than your maximum range you will hit the animal in that 6" kill zone.

Bullets lose very little of their spin in flight (relatively). They do however (relatively) quickly lose velocity. The transition between supersonic and subsonic velocities (called transonic in ballistics) has an enormous and unpredictable effect on a bullet's trajectory.

While a .22lr is not known for long range accuracy in the first place (lol), in the case of your .22 I suspect you are shooting supersonic ammo? If so the bullet will still be supersonic (and accurate) at 25yds, but will have gone through the transonic zone, become unstable, and changed it's trajectory in who knows what way, at 100yds.

Try shooting subsonic ammo. It will not go through that "transonic zone" because it is already subsonic when it leaves the muzzle, and will be more accurate at longer ranges because of it.
 
Yes a bullet is most accurate at the top of it's trajectory. That being at the muzzle of the rifle, it would be at that point a legitimate one holer. Gravity-Gravity-Gravity the same thing that keeps from floating off the ground (until they put us under it) pulls the bullet down. What part of that is hard to understand?? You then adjust the set trajectory curve to fit the conditions that you feel you need in the field,for my 22-250 is on at 200 Yrd's which puts me a little high at 100 & 150, on at 200,little low at 250, 5 1/4" low at 300. So out to 250 Yrd's it is practically a put the crosshairs on and let it rip ( at a measured 250 Yrd's I do hold the crosshairs up the 2" that is the drop, but you would not have to still hit the vital area.)
 
Its not hard to understand...I know exactly what gravity is doing to the bullet. Example, if you drop a bullet and shoot one perfectly level from the same height they will both strike the ground at the same time (given they are level surfaces). My question wasn't what is gravity, it was if sighting in my different rifles at the range that their trajectory meet your line of sight was a good idea that's all. So, pretty sure your hard to understand comment was out of line.
 
I know most are, but I know the trajectory information, I listed it in my initial post. I just wanted to get peoples thoughts on the idea of sighting my different rifles in at each rifles MPBR (I think is the abbreviation) it was not to get people to talk to me like I'm slow.
 
Sorry if you think my comments were a put down,just tried to explain it in a little different way. At least 5 different people on the forum have told you the same story on how figure out what will work for you with the rifle you want to sight in. Bring up one of the ballistic programs and figure out what is best for your style of hunting,if that isn't a answer for your question then I'm not sure where you are trying to go all this.
 
Thanks, and yes I got more info then I was looking for I just wanted opinions on if my idea of sighting-in was good/bad, or being done already. I just thought of it and never knew anyone that had so was asking around.
 
I understand what you're talking about. Personally, I don't think I'd like it. With the 223 and even the 204, the hold over is gonna be pretty large.
My 223 is sighted in 2 1/4" high at 100 yards, is never supposed to be more than 3" high and becomes 3" low at around 280-285 yards.

Shayne
 
So on your .223 do you know at what ranges your two points intersect your line of sight, or you just know it's +/- 3" to ~300 and just send it...since most targets are bigger than 3", accept a head shot on a squirrel between some branches.
 
I have no idea where it's dead on at, either time. On a coyote within those ranges I hold center chest.
That is with Winchester White Box 45gr HP.
With 55 gr SP it's 1 inch lower at 100 yards, so deer out to 200 yards are an easy neck shot.

Shayne
 
What you are asking is really a bad idea, unless you're never going to shoot at any distance other than teh site in range. You are still going to have the curve to deal with but now you have no MPBR. If you ever wanted to take a longer shot you might fine you gun shoot several feet high, not inches.

Use the Winchester site I posted, review the graph, print the chart, and learn it. Shoot your gun until it becomes second nature at any distance you are likely to shoot. Until then tape the chart to your stock so you can review it if needed.

You could also buy a Leupold Mark AR with mill dots. Use the mill dots to range and use the dial to get on target. Zeiss also has a rnage finding retical in the rapid series. The top of the retical is used for ranging and he lower for hold over and windage.
 
yes, what you are talking about is extremely doable and makes a lot of sense.

You have two points your line of sight (LOS) cross your bullets line of flight. Because of trajectory, your barrel is pointed up a certain degree. At about 25 yards or so, it crosses the line of sight.

In a perfect world, free of gravity and drag, it would continue on that straight line to eternity.

We don't live in a perfect world and have to deal with drag and gravity. So as soon as the bullet leaves the barrel, it is drawn to the center of the earth due to gravity and drag from air starts to slow it down.

So you pass your first point and that's your near zero.

It continues upwards on that LOF until it reaches it apex or rise above the los. At which point it starts to curve down again.

At some point down range, it will cross your LOS again. That is your FAR zero. For most guns shooting similar ballistics, .223, .243, 7mm-08, .308, .30-06 and such, it's about 225-250 yards out.

If things are really matched up, the maximum rise or apex is about 3-4 inches above the LOS at around 155-160 yards. The point that the bullet goes 3-4 inches below the LOS is around 260-280 yards. That 8" circle is typically what is needed to get a decent boiler room shot on a deer type animal. Having a smaller kill zone will be needed for smaller animals, and larger animals afford a larger kill zone.

so if anything, hold on the low side out to 175 yards and high from there out until you get past your 4" drop below LOS. Past that, plan on doing some kentucky windage. Doesn't matter if you adjust your sights or hold over with mil-dots, it's still kentucky windage and you need to understand the difference between full force and quartering winds as well as how to read mirage. And that is where the only real way to know what your gun is going to do is sit down and shoot. And after every shot, record it into a log book to include local weather conditions at the time. Big difference between shooting at 7 am and 8 PM as well as noon.

Maximum point blank range (MPBR) is where your bullet is in that 8" circle and you could hold the sights at the same point and reasonably be certain of making a one shot kill.

Adjusting your sights to put the point of impact (POI) to LOS is what bullseye shooting and things of legend are made of.

As to who does it? It's been taught that way for over 70 years in the Army. I witnessed over 600 people do just that and shoot qualifying scores every year for 18 of them. The Marines do it pretty much the same way.

So to teach well over 20 million folks to do that over 70 years, I'd say it has some merit.
 


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