Ladder test result question

[rugerdog5]

Unfortunatlly I can't post the pics of the groups because all I have for Internet is an iPhone. The size of the groups is not so much my question. I decided to give this ladder test a try I've read alot about them but never tested it out. So I loaded up some 308s following all the steps involved, and headed for the hills. I was expecting go get a six o'clock to twelve o'clock group. Here's my question I got two groups that went from four o'clock to ten o'clock. Has anyone else had this issue or does anyone no why this would happen. I can email the pics if that would help. Thanks for the help.

 

[Miller Outdoors]

If the wind wasn't blowing a bit in that direction then I'd be looking to see if the stock was coming in contact with the barrel on one side causing vibrations.

 

[boomtube]

Like any other groups, they fall where they will. Pick the best and forget the rest.

 

[gbraach]

Yes I have seen the same general pattern. I have run a half dozen different ladder tests and seen the same right to left, low to high pattern. Only one test showed a vertical 6 o-clock to 12 o-clock trend. As to what causes the pattern, I don't know. There were no issues with the rifles and the tests were shot on calm days.

 

[rugerdog5]

Just to clearify the day was mostly calm very light breeze but the pit I shoot at is blocked on all sides from most breezes. The rifle is glass bedded and free floats all the way to the action. It's good to hear that someone else has encountered the same thing.

 

[Limbic]

My 7mag will throw groups up and down and left and right. Once I find a seating depth the bullet likes it usually get more predictable. I don't get much up and down as I get a certain powder range that has significantly smaller groups. I'm probably not doing something right though.

 

[rdsewell]

Have you looked to see if your scope is canted in you rings? If you scope is not level to your bore when you dail your scope up it will shoot off towards the way it is canted. Just a thoughtlightbulb

 

[rugerdog5]

I used the wheeler level level level to mount the scope and the scope has a bubble level inside so I know everything is good to go there.

 

[Buffalobob]

The shape and location of groups will change with powder charges. Notice the first to rows and the charge changes from left to right for both the 155 SMK and the 155.5 Berger.

This is repeatable on different days as the picture below shows when I test RWS brass with the 155.5 Berger.

On the left is the same bullet and powder at three different charges of powder. Notice that the shape of the group changes

One thing that will goof you up big time is mirage. Mirage with a twitchy gentle breeze will drive you crazy. Shoot on cloudy days if possible.

 

[rugerdog5]

Haha yeah it will except I live on the Oregon coast I haven't seen sun since October. Yes mirage will really mess with you.