The INA Model 953 is a modified Madsen M/50. It was manufactured by the Industria National de Armas S.A. in Sao Paulo Brazil under license for Madsen. Production begain in 1950. The first Model was marked M.B.-50 and was manufactured till 1953 and was marked with a large Brazilian crest. In late 1953 the Model 1953 was introduced. Improvements on the 1953 model were a larger magazine housing and a metal loop riveted to the lower right side of the magazine housing. The loop could then hold the magazine housing together. Also the retracting handle was changed on the Model 953 to the right side instead of the top as was the buffer spring and the shape of the extractor, ejector and the fireing pin. The INA Model 53 is made of stamped sheet metal. It's an open bolt design which means it fires w