You might find buying an already completed replica M1 Garand off ebay or something for cheaper. A full scale 3D print would run you likely over $200 commercially (would have to be done in pieces, and 3d model modified to do so), also may have to pay for the 3d model file if you can't find a free one. Can be cheaper if you get someone to do a favor. It would also require painting after, and may not be the most durable to have a child handle.
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