Are all ballistic charts for a rifle caliber uniform for different ammunition?

[windymtnman]

My question for you "experts" this.
Is a ballistic chart for a certain caliber rifle pretty uniform for all the various ammunition you can buy for that caliber?

Here's my situation. I have a Browning A bolt in 30.06. It's never been a tack driver, even out of a lead sled on my range. I don't want to get a new rifle however. A few years ago, I decided to see if a supposed higher quality of ammo would group better out this rifle? I started using Hornady's SST 165 grain ammo. I thought these rounds grouped better, however the rifle still isn't as good as I'd like. I thought sighting in with a lead sled on a table, should minimize my errors. (?)

I just ordered a laser range finder, as I thought knowing the specific range would assist me in evaluating the point of aim in the field. I'm wondering if the ballistic charts will vary to any degree from one ammo to another? I want to know my point of aim, with a known distance, or even when I ought to pass up on a shot.

Your thoughts?

 

[schmalts]

Yes they will differ. The manufacture will usually list the ballistics on a website. The downside is, have been told, but not verified that some manufactures stretch the truth a bit on velocity for advertising sake. Will it make a huge difference in under 500 yard shots?? not much, but for true long range practice and shooting it will. Best bet is to always chrono your end choice of loads.

 

[nhn2a]

I second the above response. The ammo can make a big difference. Hornady SSTs I believe all fall in their Superformance line which is supposed to go 200 fps faster than most normal rounds which effect the trajectory. I shoot that same caliber and round and just recently shot through a chronograph. My bullets were actually flying slightly faster than the velocity advertised.

 

[std7mag]

No, they are not equal.

Different length barrels.
Did they use a test barrel, or an actual firearm?

Just way too many variables.
You can try different weight bullets, and from different manufacturers.
But you would be almost cheaper off handloading.

 

[Doublecluck]

The only ballistic chart anyone should use is one they verify...

 

[mtmuley]

The only ballistic chart anyone should use is one they verify...

Yep. Shoot it. mtmuley

 

[rammac]

Not to be rude but it sounds to me like your accuracy problems are due to you needing to study about ballistics in general.

Ballistic charts are only good for the rifle, ammo, and ambient conditions that existed when the chart was made. Trajectory charts are from the manufacturer are usually pretty useless because you don't know what conditions existed when they were developed. All mathematical calculators are only estimates and, depending upon how complex they are, some are useless and others can be pretty close. But regardless of how good the calculator is you still need to pick one kind of ammo and actually verify the trajectory out to the maximum ranges that you plan on shooting. Then you need to understand how to estimate the changes to the chart's drop numbers when the weather, altitude, and terrain changes.

 

[Gr8bawana]

What kind of groups are you getting and what are you looking for?

 

[cahunter805]

Throw the lead sled in the trash!! They can cause many problems and even crack your stock. I use a bipod and rear bag or a front rear and rear bag.
Is your rifle all factory? How is it shooting currently?

 

[BucksnDucks]

Ballistic charts are only as good as the VERIFIED info that is put into the calculator. Also your rifle, optics, and environmental factors will effect accuracy.

I started with a 30-06 and used that rifle for decades. Factory rifle with factory Core Lokt ammo. Sighted 2.5 inches high at 100 yards with around a 350-400 yard max. Hunting and shooting was much simpler then.

 

[Majja]

Like all have said it is better then no data at all. But the bullet velocities will vary from gun to gun. I would verify your dope at the range. If you have a Chrono verify your velocity and then plug it in to one of the online ballistic Calculators to get a much closer idea of your dope.

 

[rammac]

It struck that the OP may be thinking about the physics involved in the drop of a bullet. If you are wondering about gravity's effect on bullet drop then yes, all bullets will drop at the same rate due to the pull of gravity being pretty consistent anywhere on the face of the earth. The trajectory of any specific bullet though is going to be controlled by how long the bullet is in flight, a faster bullet will have less time in the air and therefore will drop less at any specific distance compared to a slower bullet. Depending upon what is held constant, you can change the speed of a bullet in many different ways; changing barrel length, changing powder charge, changing bullet weight, changing bullet shape, etc.

 

[elkdreamer]

It struck that the OP may be thinking about the physics involved in the drop of a bullet. If you are wondering about gravity's effect on bullet drop then yes, all bullets will drop at the same rate due to the pull of gravity being pretty consistent anywhere on the face of the earth. The trajectory of any specific bullet though is going to be controlled by how long the bullet is in flight, a faster bullet will have less time in the air and therefore will drop less at any specific distance compared to a slower bullet. Depending upon what is held constant, you can change the speed of a bullet in many different ways; changing barrel length, changing powder charge, changing bullet weight, changing bullet shape, etc.

They way I understand it is this. The bullet speed does not effect how long it is in the air. It does however effect how far it travels before it hits the ground. This is why a faster bullet has a flatter trajectory. Am I wrong?

 

[Gr8bawana]

They way I understand it is this. The bullet speed does not effect how long it is in the air. It does however effect how far it travels before it hits the ground. This is why a faster bullet has a flatter trajectory. Am I wrong?

Think of it this way, if you drive your car someplace 100 miles away going 50 mph and then drive back going 75 mph is it going to take you the same amount of time?

 

[rammac]

They way I understand it is this. The bullet speed does not effect how long it is in the air. It does however effect how far it travels before it hits the ground. This is why a faster bullet has a flatter trajectory. Am I wrong?

True, gravity effects how long it's in the air and velocity determines how far it goes while it's in the air. The faster bullet has what is described as a flatter trajectory because it travels farther for each increment of vertical drop compared to a slower bullet (in reality both bullets fall the same amount in the vertical direction but one covers more horizontal distance before it hits the ground). But when we talk about bullet trajectory we are discussing how long it takes to impact a target that is positioned at a point in space before the bullet impacts the ground. This is why we say that the trajectory is effected by how long the bullet is in flight, when we shoot at a target we keep the distance constant while we change the velocity. When the velocity is increased it will take less time for the bullet to impact the target at the specified distance as compared to a slower bullet. How long the bullet takes to reach that target will determine how long gravity will effect the drop of the bullet; a slower bullet takes more time to impact the target and gravity pulls the bullet down more, a faster bullet takes less time to impact the target and gravity pulls it down less.

 

[TheJason]

My question for you "experts" this.
Is a ballistic chart for a certain caliber rifle pretty uniform for all the various ammunition you can buy for that caliber?

That all depends. External ballistics depend on 1) the velocity the projectile is traveling at, 2) the drag (or ballistic) coefficient of the projectile, and 3) the mass/sectional density of the projectile. If these are the same or very close, you can expect the ballistic charts for each to be the same or very close. Change one of these variables and you are suddenly comparing apples to oranges.

Edit: I agree with the above folks who told you to verify your ballistics on paper.

 

[Bydand]

The only ballistic chart anyone should use is one they verify...

This is the best response I've seen to any question of this type.

Even more specifically, though, don't use any ballistic chart unless you've made it. If you're talking about 100-yard shooting, there are way too many variables to address. If you're talking about 1000 yard shooting, there are way too many variables to address.

The best "general" advice I could give is to never shoot an animal beyond half the range you're comfortable shooting at the range.

 

[rammac]

In my experience anybody that can't get a ballistics chart to match up to their true trajectory simply doesn't understand ballistics. The obvious proof that ballistic charts work is the fact that the military can predict the impacts of artillery shells and missiles. I always create a chart and the verify it at the range. Any minor changes are noted and then I keep the chart for future reference. The problem is that most people don't understand ballistics and rather than becoming better informed they simply dismiss it as useless mumbo jumbo. You have to know enough about the science to be able to recognize how the current shooting conditions will cause your bullet to deviate from the chart you created under range conditions.