I once worked in a sawmill in Northern Idaho. During coffee breaks we used to do some shooting with pistols in the saw filing room. Everything from 22 to 44 mag. For a target backer, we set up tamarack 12x12 blocks two deep. We shot at this for a while then one day, I fired a shot with a Ruger 41 and noticed a glint of light. I walked over and looked through the hole which had appeared and had a pretty good view of the church on the other side of the log yard. Wood backstops don't work. Happily, the church was unharmed and the pastor was unaware of our transgression. Regards, Bill.