270 WSM ladder test

[guhunter]

This is my first attempt at a ladder test. It was shot at 315 yards. I'd like someone more experienced than I with this type of testing to take a look and give me some advice.
http://img831.imageshack.us/img831/3103/laddertest.jpg (http://imageshack.us/photo/my-images/831/laddertest.jpg/)

[guhunter]

http://img24.imageshack.us/img24/9360/photo1wnk.jpg (http://imageshack.us/photo/my-images/24/photo1wnk.jpg/)

darkened the writing

[coldmaker]

i would think you may have something at 69.5 gr. i would try there and play with col.

[squirrelsniper]

One thing to keep in mind... with ladder tests, even though you certainly can't ignore windage changes, you're mostly focusing on getting a tight group in terms of vertical dispersion. You're basically looking for a spot where the velocity is relatively stable even with slight powder charge differences. If the velocity is stable with powder charge changes, then the "in-bore" time of the bullet is going to be similar from shot to shot and therefore the harmonics of the barrel are going to be very similar for each shot.

I'd say the 69.8gr to 70.4gr range looks most promising. I'd probably go with something around 70.1gr and try 2 or 3 groups at the same range and see how things go.

There may also be another node in the 71.0gr to 71.6gr area, but I like the looks of the other one better.