How to zero-in a scope (rifle)

pierrecham · 11-30-2006, 05:00 PM

Hi guys,
I'm getting a Weatherby Accumark 30-378 after X-mas and planning on putting a Leupold VXIII 8.5 x 25 x 50. In my area, ranges have a maximum of 100 yards. I want to zero myrifle to 300 and maybe 400 yards and also try 500 yards. In the Weatherby catalog, it says that a 30-378, 180 gr, bullet will have the following trajectory when zero at 300 yards:
+2.4 at 100 yrd, + 3.1 at 200 yrd, 0 at 300 yrd, -7.4 at 400 yrdand -19.6 at 500 yards.
Now, if my target can only be at a maximum of 100 yards,how many inches above the bulls-eye must the hole be in order be able to say that the rifle is zero at 300, 400 or 500 yards? How do I figure that out? If I buy a scope with Boone & Crockett reticle and zero-in at 300 yards, will the lower reticles on that scope mark 400, 500, 600, 700 yards?
Thank You,

stubblejumper · 11-30-2006, 06:00 PM

Sighting in at 100 yards and then shooting at game animalsat 400 yards or 500 yards without actually shooting the load at targetsat those distancesto verify the trajectory,isa recipefor wounded or missed game animals.I verify every load by actually shooting out to 500 yards and I have seen the actual trajectories vary from the ballistics chartsby several inches at 500 yards even when the loads were chronographed so the exact muzzle velocity was known.If you don't even chronograph the loads,and are estimating velocities the error could be even worse.I have far too much respect for the game that I hunt to ever shoot at any animal at any distance that I have not practised on targets with the load that I am going to hunt with.

Ridge Runner · 11-30-2006, 06:36 PM

In a sporter weight will the 8.5x25 have enough eye relief?
Anyway stubble is right you must confirm your POI at various ranges, and may need to tweak the BC of your bullet on your ballistic program so it matches your actual trajectory. altitude will change your BC, it can go from .64 at sea level to .9 at 5000 ft, this will drasticly change your trajectory.
I personaly run my sight in to 700 yds to be sure my POI jives with my POA.
RR