I built a muffle box when I lived in upstate NY, it was positioned in the back of the open barn to shoot against a far hillside. I had neighbors on both sides and they never heard anything. You can go fancy with a plywood box lined with fiberglass insulation like I had or just stack tires together.

They're a PITA to move around so are best for positioning and shooting at a stationary point like a target frame, but they do work. Don't know from personal experience how well a set of tires by themselves reduce noise but my muffler would reduce a centerfire rifle or 12 gauge shotgun to a dull "poomph" even standing a few feet to the side.

Gunnery, gunnery, gunnery.
Hit the target, all else is twaddle!