Pellet B.C's

[scaramanga]

Does anyone know where I can get a list of pellet ballistic coeficients, Im particularly interested in the the H&N Barracuda.

cheers

[Shed tuner]

in .22 it's about 0.030

[scaramanga]

Originally posted by BuddyBoy
in .22 it's about 0.030

Cheers good man

[bedlam]

I dont have a clue what you mean by B.C'S ?
i am trying baracuda,s in my hw95 in .177...any idea what their B.C is ?

[Paul Hudson]

BC - Ballistic Coefficient. Semi-mystical number used in trajectory calculations .

It varies from pellet to pellet, barrel to barrel and even from shot to shot. As long as you're hitting what you aim at, I wouldn't worry about it.

It makes a handy starting point in software such as Chairgun, but personally I've found it's better to use empirical measurements - velocity, pellet weight and pellet drop at a known distance.

Paul.

[scaramanga]

Originally posted by Paul Hudson
BC - Ballistic Coefficient. Semi-mystical number used in trajectory calculations .

It varies from pellet to pellet, barrel to barrel and even from shot to shot. As long as you're hitting what you aim at, I wouldn't worry about it.

Paul.

To be honest I wouldnt normally bother with it for pellets but my sierra ballistics software that I use for my HMR and my .222 wont let me make a calculation on trajectory and such like without adding it in to the equation

[foxshooter]

Originally posted by Paul Hudson
BC - Ballistic Coefficient. Semi-mystical number used in trajectory calculations .

It varies from pellet to pellet, barrel to barrel and even from shot to shot. As long as you're hitting what you aim at, I wouldn't worry about it.

Paul.

Excuse me but thats utter utter ballcocks

BC varies from pellet type to type obviously eg Wasps to Accupells as pellets have different shapes, sizes and sectional densitys.

BC will change very very very slightly as the pellet slows down in flight but thats it.

To summarise

Ballistic Coefficient (BC) is basically a measure of how streamlined a bullet is; that is, how well it cuts through the air. Mathematically, it is the ratio of a bullet's sectional density to its coefficient of form. Ballistic Coefficient is essentially a measure of air drag. The higher the number the less drag, and the more efficiently the bullet cuts through the air. So for purposes of flying through the air efficiently, the bigger the BC number the better.

BC is what determines trajectory and wind drift, other factors (velocity among them) being equal. BC changes with the shape of the bullet and the speed at which the bullet is traveling, while sectional density does not. Spitzer, which means pointed, is a more efficient shape than a round nose or a flat point. At the other end of the bullet, a boat tail (or tapered heel) reduces drag compared to a flat base. Both increase the BC of a bullet.

Mark