Is this legal, 2x4 staked to the ground to preload against? From what I can find, they only talk about something underneath the bipod
https://www.google.com/url?sa=t&source=web&rct=j&url=http://competitions.nra.org/documents/pdf/compete/RuleBooks/HPR/hpr-book.pdf&ved=0CBsQFjAAahUKEwiN563AjrnIAhUEOz4KHcu_DCI&usg=AFQjCNGjInLP56IwF1oOvj6j4jQ1ASOYbw&sig2=EuiB5qp5Jh325uvGD8JH2ww
https://www.google.com/url?sa=t&source=web&rct=j&url=http://competitions.nra.org/documents/pdf/compete/RuleBooks/HPR/hpr-book.pdf&ved=0CBsQFjAAahUKEwiN563AjrnIAhUEOz4KHcu_DCI&usg=AFQjCNGjInLP56IwF1oOvj6j4jQ1ASOYbw&sig2=EuiB5qp5Jh325uvGD8JH2ww
