Has anyone here built/used a sawdust bullet trap? It's been 6yrs since't we've had a decent snowbank so I gotta' do something. I'm building a sawdust-filled trapper I think, a local mill is offering 1000lb bags of sawdust for 20 bucks/bag Fir, cedar, hemlock, alder, maple etc ......OR...... I just spoke with him and he said "I have a hard time getting rid of Black Walnut" I can probably get the Black Walnut for free..... I'm thinking I need about a ton and a half of sawdust. Any thoughts?