Heavy bullets vs.light bullets

[Crazycooydog]

Are heavy bullets always better,or where is the line between the two.

lighter bullet with say a bc of .355@3800fps
heavy bullet with say a bc of .420@ 3300fps

I know energy is the big dif but some times the lighter bullet with more speed beats the wind better.This is more directed towards long range coyote hunting.

heavy,slower bullets in a larger cal as aposed to lighter faster bullets in a smaller cal.
It is ALL about bc. numbers is'nt it???

Are the balistic programs allways right in the number they show.

[ 03-10-2004: Message edited by: Crazycooydog ]

 

[ottsixx]

Idont even worry about the BC as Im a lot more concerned with the rate of twist in the bore and what bullet I choose to shoot thru the bore for propper bullet stabilization,my drive in the game is to hit a nickel at 100yds or qa golf ball at 300 yds and if I can do that then I feel confident that I can take the heart out of anything that walks out to 300 yds and if I can take his heart out then he isnt going far..............................

 

[Fiftydriver]

The bullet examples you list really are not that far apart and the "high BC" bullet is not really all that high and the "low BC" bullet is not really all that low. To be honest, they are both medium range BC bullets.

I am really suprised at the velocity spread in your comparision as the BCs are really not all that far apart which would tell me bullet weight would likely not be much different if same caliber. Perhaps the case capacity is dramatically different in your comparision between the two which we do not have that information.

There is never a BEST choice, there are better choices for sure but it all depends on the situation and many different bullet will work in several different situations.

In reality, if your shooting under 500 yards, the lightweight, high velocity bullets will generally shoot flatter then the heavier slower bullets even if they have a dramatically higher BC.

If its windy, the heavy bullet may have an advantage at 500 yards but likely they will be very close simply because of the velocity advantage of the lighter bullet.

If you stretch things out to past 1/2 mile, the higher BC bullets will nearly always make hits easier at these ranges and farther, especially when its windy out or even breezy. Does that mean they are the best bullet, depends on what your doing and what you need the bullet to do once it arrives on target.

Simply put, there is never a single best bullet design, many will work, some are just better then others at certain things.

 

[noel carlson]

Kirby,

I think your answer a great generic summary.

If, however, the target type, worst anticipated ambient condition, and maximun range at which that target will be engaged is specified... would you entertain the idea that there is always an optimum projectile/charge/barrel combination?

Best,
Noel

 

[MontanaRifleman]

There are only two things that affect wind resistance. Velocity and BC. Heavier bullets tend to buck wind better because heavier bullets uusall have higher BC's, but not always, depending on their shape.

As Kirby mentioned, it depends on the situation and the kind of shooting you are doing. Lighter and faster bullets will have a flatter trajectory in short to medium ranges, but then they loose velocity quckly due to their lower BC.

The best way to detirmine which bullet is best for your application is to crunch the numbers in a ballisitic calc using likely BC and velocity.

-MR

 

[Leupold308]

The best solution would be to run a exterior ballistic program, like montanRifleaman mentioned. Ive been using the Sierra ballistic software for almost 8 years,serves me well. And its relatively inexpensive. Oh ya and if you plug in the envirnment parameters thier usually pretty accurate.(i sometimes bypass that operation when getting rough estimates)

 

[Locknload]

"Are the balistic programs allways right in the number they show."

Yes, the programs work on math formulas and all of the info you give or have is math based. So if the data inserted in the program is accurate, the results will be accurate.

If you want to see this work, take a look at the program Silhouette Ballistics. It allows for a great deal of data imput including, temp, pressure, humidity, altitude, wind, BC, velocity, scope settings and the actual true scope adjustments for your scope. It will give you sight setting in 25 yard increments out to 1,000 yards that are accurate based on your zero distance.

I have used the program to convert my normal sea level, high humidity shooting location's sight settings, to various locations in the US including the high desert at 4,500 ft for a world championship match.

If you put the program on a lap top you could adjust the data at the match or in the field.
Ed

 

[Bart B]

Are the balistic programs allways right in the number they show.

No.

The answers each one gives depends on the formulas used in the software coupled with the BC values of a given bullet leaving at a given muzzle velocity. BC's derived from actual time of flight tests between two points are more accurate than those derived from weight and shape.

All bullets have a small range of BC's that vary with the velocity they are moving at. Air flow around a given bullet is not always exactly the same from muzzle to target. Sierra Bullets list as many as 5 BC's for some bullets in 5 different velocity bands. Other bullet companies as far as I know, list only 1 BC for each of their bullets. Sierra's software allows different BC's and velocity bands for each BC a bullet has in each of those bands. I don't think other software does.

In my own tests from measured bullet velocities, sight movements and atmospheric conditions, Sierra's software has produced sight settings for ranges up to 1000 yards within 1/2 MOA of exact for several of their 30 caliber match bullets at different muzzle velocities. For me, that's about as accurate as one can get.

Using a few other ballistic software sets I've tried, the drop numbers vary somewhat compared to Sierra's. Berger Bullets' software is the closest to what Sierra's gives for answers.

Do your own experiments and use what you're comfortable with.

 

[barnesuser28]

Sierra's software allows different BC's and velocity bands for each BC a bullet has in each of those bands. I don't think other software does.

shooter allows you to enter more than one B.C

 

[Bart B]

shooter allows you to enter more than one B.C

With a high and low velocity limit for each one?

 

[Broz]

With a high and low velocity limit for each one?

You enter MV and then you enter the BC and a low velocity limit for that BC, then the next BC and also a low vel limit and so on. The last BC entry has to end with a zero velocity. I don't know how many entries you can make but I know I have entered some with I think over a dozen.

Bryans New Applied Ballistics app has that option also and it also has an option to do your own custom drag models too. This is said to be best used for transitioning bullets going subsonic. I have the app but have not yet got familar with the custom drag model option.

Jeff

 

[Mikecr]

There are only two things that affect wind resistance. Velocity and BC.

This is wrong, and so are notions of high velocity trumping BC.

Wind drift comes down to Time Lag, and distances wind drift deviations(resulting from time lag) are applied.
The more a bullet SLOWS(decays in velocity) the greater wind influences it's flight.
That slowing rate is tied to BC.
The only time higher velocity 'seems' to reduce wind drift(as calculated), is when BC rises with velocity.
But if your drag curve matches your bullet, BC does not rise with velocity(and drag still does).

Lighter/lower BC bullets slow down at a higher rate at any velocity, and highest near the muzzle. This is one reason near wind matters most.
So provided BCs are valid at velocity, lower BC bullets ALWAYS drift more with a given wind than higher BC bullets, regardless of velocities.

 

[Broz]

Wind drift comes down to Time Lag, and distances wind drift deviations(resulting from time lag) are applied.
The more a bullet SLOWS(decays in velocity) the greater wind influences it's flight.
That slowing rate is tied to BC.
The only time higher velocity 'seems' to reduce wind drift(as calculated), is when BC rises with velocity.
But if your drag curve matches your bullet, BC does not rise with velocity(and drag still does).

Lighter/lower BC bullets slow down at a higher rate at any velocity, and highest near the muzzle. This is one reason near wind matters most.
So provided BCs are valid at velocity, lower BC bullets ALWAYS drift more with a given wind than higher BC bullets, regardless of velocities.

Well, Thanks for posting this. I guess I never new the technical reason or how to explain it, but, heavier higher BC bullets have always trumped lighter faster bullets in my wind drift testing in the field. Thats why I go big. Bigger BC, more energy, retains velocity longer and soon becomes the faster of the two and the result is less wind drift.

Thanks
Jeff

 

[T3-OleMan]

Great explainations. Kinda like the Greyhound bus finally passes the Moped.gun)
Get er done!