ORIGINAL: yeoman
What will be the procedure? Shoot one shot, find it in the medium, record the data and repeat? Guess the medium (clay)would need to be remixed before another shot to eliminate the void from the first shot? Would it be better to use a spackle bucket filled with packed sand, complete with lid made of material, maybe tarp material, held in place by the lid from which the center has been cut, the bucket then turned horizontally? That way the sand would be held in place, the bullet would pierce the material, the medium would not have a void, the data could be collected and the material moved for the next shot and resecured with the lid. I wonder if a metal detector could be used to pinpoint the location of the bullet in the horizontal bucket to get that data, then dump the bucket through a rat wire "strainer" to another bucket thereby catchingthe bullet, and the lid resecured for the next shot?
I shot into this for my testing a few years back:
http://www.the-gleasons.com/bucket.htm
not costly, but measuring bullet depth is an issue. Expansion, weightand penetration were the primary variables. I have a MS in Statistics and to me you need to design a experiment with a couple of bullets and couple of powders and randomize the shooting so that you can do an "Two Way Analysis of Variance" on 3 variables,
penetration
expansion diameter
weight retention of the bullet
The "nulll hypothese you testing" is that "there is no statistially significant difference between a PRB and a "hornady XTP" with regard to
Penetration
Expansion diamerter
and WT retention.
That would be the experimental design I would do.
The experiment suggest by you or your son tests the null hypothese that there is no difference between distrance and penetration. You can do that with a "regression line" with the X axis being the distance shot and the y axis being distance penetration in the medium.
Chap