Ballistic Coeficient and speed

[jsthntn247]

I have a bullet with a .324 g1 bc at 2850fps. I'm shooting it at 2635. How does this effect the bc of the bullet. I'm going to shoot it at distance this weekend and need to make a drop chart that will get me close.

 

[nosualc]

Re: Ballistic Coefficient and speed

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

 

[r bose]

From what I understand advertised BC and actual BC can be different depending on many variables. I'm not the person to try to explain it. I use the Hornady ballistic calculator on their website and it gets me close every time.

My question is at what distance do you plan on shooting? Compare a 69g sierra 223 bullet loaded at 2700 FPS to what you're shooting and they will be very close in wind drift. We had a young man bring his 223 and shot this load at 600 yards, in moderate switching wind, and he couldn't hardly stay on target. He said they "shot great" at 100 yds. He learned a hard lesson in distance shooting that day. Shooting groups at 100 is totally different than shooting 600 and staying on paper.

Good Luck

 

[Joe R]

nosualc gave you the best ballistic calculator that I know of.

 

[Brians356]

For background understanding: There's a pretty good discussion of BC vs velocity in Sierra's reloading manual. Worth a read. They list BCs for two or more velocity ranges, a unique practice (still?) among the popular books.