Likewise an M-1 carbine receiver and an M-2 carbine receiver are identical, and all the parts to convert a gun from an M-1 to an M-2 are available on the surplus market. HOWEVER having all the parts, and an M-1, or even just some of the M-2 parts together, is a machine gun under the NFA. While the US Supreme court decision in the Staples case should help to protect truly innocent possessors of such things, you are playing with fire.

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7342. Penalty for refusal to permit entry or examination. Any owner of any building or place, or person having the agency or superintendence of the same, who refuses to admit any officer or employee of the Treasury Department acting under the authority of section 7606 (relating to entry of premises for examination of taxable articles) or refuses to permit him to examine such article or articles, shall, for every such refusal, forfeit $500.