Load Testing

[Dye]

How can a person take personal preferences out of load testing?

Be carefull Dye

[Bass Ackward]

Dye,

Some questions here. One of the reasons I can think of NOT TO is because of benifit from past experiences gained.

But to answer your question, using a systematic approach with a written or established guideline may help. Example: Say you are biased to choking with bullet diameter. You may want to try every other technique that you can think of using choking as the last test.

But if choking has always worked for you in the reloading style you like, why would you not want to benifit from this knowledge and try it first?

[waksupi]

How can a person take personal preferences out of load testing?

Be carefull Dye

by testing every concievable variation, and comparing targets afterwards. The best target, wins.

[joeb33050]

How can a person take personal preferences out of load testing?

Be carefull Dye
By having someone else shoot and measure groups.
Personal bias has led to many examples of erroneous scientific results, cold fusion being one result. There's a whole field of study about how we are blind to results that we do not expect to see, and how we "adjust" results to what we do expect.
For a boring time see "Bias in Mental Testing" by ?Herrnstein?".
Then, a properly designed experiment is needed, keeping in mind that lots of groups are needed to demonstrate small-group-size differences. As a note, when shooting sets of five 5-shot groups, on average the largest group size will be twice the smallest group size. 1" to 2". That's when everything is the same.
joe b.

[44man]

This can apply to your powder choices too. If you swear by a certain powder and try it in another caliber but only one charge amount shoots a decent group, you should try another powder. You should be able to vary the charge up and down a little without a drastic change in the group size. In other words, when you start with the lightest load and work to max, there should be no sudden changes, just a small, steady tightening of the groups to the best load, then when that load is passed, a small, steady increase in group size. This will allow you to shoot good groups in any weather condition.

[44man]

There is one very important bias I forgot to mention and that is the idea that the gun must be shot as hot as possible, after all, it's a magnum. This train of thought will defeat you right at the start.
Like joeb said, I have watched guys just pop off the lighter loads with no care, but put their all into the top load because thats all they expected to work and all they wanted to work.