3d print stand legs for the Ikea Harvmatta 24x35x6 cm document box. I filled the harvmatta box with 2.25kg of Plumbers Mate sealing paste (very similar to duct seal) on the bottom, use some magnets to hold up targets - or just put targets/toy soliers or other folley onto the the plumbers mate and it holds in place just fine. Lead pellets stick to the surface of the plumbers mate, steel bb's typically stick, but can fall off/bounce out - so recommend using magents to put a paper target over the enitre front (the bb's won't bounce back through the paper/card. The Harvmatta box, with the weight at the back won't quite stand up on it's edge alone, as the lip around the rim tips it off balance - and the centre of gravity is too close the the edge. The legs make the whole target very stable, either landscape or portrait.