RCBS ballistics program help needed

[Len Backus]

I lost my copy of this program and no longer have it installed on my computer.

Does someone have it and can you do a calculation with it for me, please? It concerns the shift in point of impact resulting from improperly rotating (canting) your rifle on its rest.

Assume:
BC of .750
velocity of 3200
range of 800 yards
rifle canting angle of 3 degrees

Thanks

 

[Dave King]

Len

I don't have the program but about 5 months ago I spend a fair bit of time examining these "rifle cant" problems. It's definately some to consider with each shot.

 

[*WyoWhisper*]

Len,

I needed the caliber .. but I used the 300 gr. 338 bullet for the 750 BC..

The program says at 800 your off by 1.28"

let me know if ya need more calculations done....

 

[Darryl Cassel]

Ric
The actual field testing of the 300 gr 338 bullet comes up to .797 BC instead of the .750 BC that is posted.

Len
For target work, the canting can be off in 1000 yd matches and make a change on your group size if the rifle does not track well.
For hunting, the small amount of difference on a deer size animal really does not come into play that much. At 1 or 2" your not going to miss your game.

DC

 

[Len Backus]

Thanks, guys.

I know it's a significant issue if you cant much more than 3 degrees at long range which could sure happen when shooting prone off a bipod on uneven terrain.

My rifle wears an anti-cant bubble level to make me aware of the issue.

 

[*WyoWhisper*]

All my rifles do as well!!!! Neat little device !!

 

[Guest]

Where can I get one of these anti Cant Bubbles?

 

[Len Backus]

Anti-cant device

It is very easy to mount and use. Around $30

 

[*WyoWhisper*]

The one I have is in Brownell's.. There are ones that attach to the picanniny rail or the tube of your scope. I think Sinclair's also carries them....