Range Report How to figure come-ups when using diff. bullets?

[NativeCraft]

Shooting a WOA 1:7 twist 20" Service Rifle.
I'll be shooting Horn. 68 gr. at 200 and 300 yds.
Can y'all help me figure how to get on paper at 600 using an A-Max 80?

 

[ChadTRG42]

Re: How to figure come-ups when using diff. bullets?

Run the velocity and the BC of the bullets you have into this program, and it will tell you your come ups. If you are sighted in for 1 bullet, there may be a slight point of impact shift with the other one. So, you may need to re-zero, or just spot your hits at distance and make an adjustment to be dead on. At 600, the 80 grain will hit a little higher than the 68.

http://www.mega.nu:8080/traj_dat.html

 

[mattj]

Re: How to figure come-ups when using diff. bullets?

http://www.jbmballistics.com/cgi-bin/jbmtraj_simp-5.0.cgi

You'll need chronographed (or approximated, based on load manual or anecdotal information) muzzle velocities for each load.

Punch both loads in, uncheck "elevation correction for zero range".

Look at the difference in drop in the MOA column between the 68gr load at your zero range and the 80gr load at 600. That will be your approximate sight adjustment (in MOA) for your 80gr load.

-Matt