Target Shooting Box Built

Would’ve liked to see how you affix or situate the steel plate. Nice looking box. Is there a way to remove or extract the pellets from the duct seal?
In my target box I stuff old bed sheets and blankets in between the target and duct seal. This prevents the pellets from reaching the duct seal. To empty out the pellets I pull out the sheets and shake out the pellets onto a tray.
This method is faster than picking the pellets out of the duct seal and the duct seal never needs to be replaced.