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Software for establishing B.C. for conicals???

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01 March 2004, 13:40
patncor_2000
Software for establishing B.C. for conicals???
Is there any free ware around for establishing a ballistic coefficient for conical muzzle loading bullets when the maker has failed to do so? My main reason for this is to figure trajectories for any conical I choose to shoot like the 50cal. 260,320gr Lee REALS and the Lyman 400gr minnie.
01 March 2004, 14:59
Savage99
www.uslink.net/~tom1/calcbc/calcbc.htm
01 March 2004, 18:46
patncor_2000
Thanks savage99
Im off to get my calipers and conicals.

PW
04 March 2004, 10:44
Brent
If you want to figure out the BC empirically and over the range that you normally shoot (BC changes with velocity so it's not the same at 100 yds and 300 yds for example), then gather some velocities at two knon distances from your muzzle and punch them into the following:
http://www.eskimo.com/~jbm/ballistics/ballistics.html

I wager that the BC you actually experience will be lower than the one you calculate from bullet shape measurements.

Brent
07 March 2004, 11:01
patncor_2000
SO The bottom line is setting up my chrony at 25,50,75 and 100yds and recording the velocities and powder charges out of a specific pistol or rifle is the only true way to establish trajectories and remaining energy for a given projectile at a given distance. For large diameter muzzle loading projectiles that is. WHEW
06 March 2004, 16:36
RandyWakeman
Quote:

If you want to figure out the BC empirically and over the range that you normally shoot (BC changes with velocity so it's not the same at 100 yds and 300 yds for example




Brent is right on target. No "static" B.C. is remotely accurate.

http://www.chuckhawks.com/bc_not_exist.htm
07 March 2004, 11:17
Savage99
Randy Wakeman,

Since the Ingalls charts were used for years before chronographs for military and sporting use I wonder at your statement. Perhaps you could provide some facts?

I have used the Ingalls charts as provided by Dupont and found that they were very close to what Sierra publishes. Since Sierra tests their bullets this seems that the charts are indeed close.

And why should they not be close anyway?
08 March 2004, 19:24
RandyWakeman
Quote:


I have used the Ingalls charts as provided by Dupont and found that they were very close to what Sierra publishes. Since Sierra tests their bullets this seems that the charts are indeed close.




Not at all, which is why Sierra corrects the flawed G1 drag tables with three distinct velocity based BC's.Olin uses their own Doppler radar range, as does the U.S. Military.