Let me know if you need some wood panels. We throw away a ton of plywood panels that are 1/4 to 1/2 thick. They range any where from 12" to 14" by 18"to 24". I have access to tons of pallets and some wooden crates.
I have been battling a shoulder problem. This my strong side so even practicing drawing a pistol or shouldering a rifle has been difficult. Injury can be an issue as well.