Ballistic coeff and sectional density of cast

[harley45]

How do you guys figure these for your ballistic calculators?
I just got one of these and found a problem with this when I went to enter my load data.

[felix]

Simply use .180 for the majority of flat nosed boolits for their respective bore size; or .220 for those boolits slightly heavier than nominal. The value picked won't make any difference below 150 yards or so. If shooting long range, then pick the load with the smallest ES and the sharpest point on the heaviest boolit. ... felix

[harley45]

Felix. this is my first ecperience with a program like this for an example if I'm using a Lyman 452423 the b.c. should be .220? since this is flat nosed boolit of slightly heavier than norman weight for a acp. with this gun I will be under 150 yds but when I start my .308 project next month I'll at least have some experience with the program. What about the sectional density or does that not matter at all?

[Bass Ackward]

Felix. this is my first ecperience with a program like this for an example if I'm using a Lyman 452423 the b.c. should be .220? since this is flat nosed boolit of slightly heavier than norman weight for a acp. with this gun I will be under 150 yds but when I start my .308 project next month I'll at least have some experience with the program. What about the sectional density or does that not matter at all?

Yo Harley. Life shouldn't be difficult. Try this to do your sypherin.

http://www.handloads.com/calc/

[BCB]

The website Bass Ackward mentioned seems to work O.K. I have used it and the points of impact are fairly close as I have experimented with different loads at various velocities.
I use my chronograph to calculate B.C. if it needs to be "really close". I get the velocity of the boolit at the muzzle (actually 1/2 dozen feet away) and then at 25 yards. NOTE: ONE MUST HAVE A VERY ACCURATE LOAD SO AS TO GET THE BULLET BETWEEN THE SCREENS of IT'S oversville FOR THE CHRONY! There are several programs available to calculate B.C. using the 2 velocities. Ain't sure where I have found them since it has been sometime since I have done that method. Good-luck...BCB

[C1PNR]

Hey, BA, thanks a bunch for that link. Pretty much takes all the mystery and conjuring out of it.

[harley45]

Wish I'd seen that link before I bought this stupid lee program

[drinks]

Harley;
The Lee catalog gives the B.C. of most of their bullets, you can look at the Lee weights and shapes and make a close guess at other's .
The Lyman Cast Bullet Handbook has the B.C. of some of the Lyman bullets listed.
The Lee program has a learning curve, but does well when you learn it's quirkes.
Huntingbiz.com has an online point blank calculator that is pretty easy to use.
Don