How do I figure the effective point-blank range for a load? My starting figures are probably a six-inch circle hit by a 250 gr. bullet from a .338 Win. Mag. Muzzle velocity will likely be in the 2,600 fps area.

kk

Since I'm not sure what bullet you use just type in the info on the below link and alter the "Zero" range until it meets what you want. That's what I use for my loads. Ballistic calculator

Figgure +-3" out to 250yards (or so)
A 250gr partition at 2660fps is +2.78@100yd, +3.00@127 3/4yd, 0@225yd, and -3@265yd.
Different bullet, and/or different actual MV will change it slightly.

For a quick idea on the trajectories of some of the bullets you use, take a look at the ballistics tables for factory ammo found in the back pages of the "2003 Guns & Ammo Annual."

If you can duplicate (at the range) the velocities listed on the tables for the right bullet, the POI's at different distances should be close to those numbers shown. To make sure, place a couple of targets at 200 and 300 yards and follow the tables.

For example, a 250-grain NOS Partition at 2,700 fps, fired +1.9" at 100 yards, should drop to -7.7" at 300 yards.

[ 04-19-2003, 22:23: Message edited by: Ray, Alaska ]

From the link supplied by NB Hunter and from the other responses, it appears I should zero the gun at around 300 yards. Is this about right?

kk

0@225yd

Send me (use the e-mail link above) the factory load your using (or the bullet your reloading with) along with your actual muzzle velocity, scope height, height above sea level etc. and I'll (let the computer) figgure out your actual trajectory.

I sigted mine in for 210 yards and it hold within 2.5 inches from line of sight out to 250 yards. If you mentioned a 6" zone you could sight in around 225- 230 yard, but you don't really gain much for distance.

Steve's Page has some good programs here.
http://stevespages.com/page8b.htm

I downloaded and use the Point Blank. It will give you what you are looking for, and more.

Jerry