I looked at your report, and there are at least 3 pieces of info/questions that stick out.
1. What is the average value that you have to hit? What did the one sample that passed hit?
2. "Absorbed energy levels below 6J are outside the verified range." Out of 6 values, you have 1@7J and 1@6J, and the rest are below 6. 66% of your sample values are suspect.
3. There is a fair amount of info on the interweb (I know, I know) that shows the NDT of A36 at about -40 F, and you are testing at -45 F. Gonna be tough. (or not)
BTW, you have to chop off the characters after the ".pdf" to see the report
There seems to be 3 main impact measures, related to the %ductile vs.brittle fracture. The report shows 5% ductile failure, so you are virtually at the end of the curve.
http://www.uvm.edu/~dhitt/me124/CharpyImpactNotes.pdfI would be shopping for some different base metal