If you plan on buying a gun in Nevada, better hold off on the medical marijuana card. The ninth circuit court of appeals says the federal ban on gun sales to card holders is constitutional. The court says a ban on the sale of guns to marijuana and other drug users is reasonable because the use of such drugs “raises the risk of irrational or unpredictable behavior with which gun use should not be associated.” The decision came in a lawsuit filed by a Northern Nevada woman who tried to buy a gun in 2011 after getting a medical marijuana card. The gun store refused, citing the federal rule on the sale of firearms to illegal drug users.