In 1970, the Policia Militar do Rio de Janeiro (PMRJ) asked the services of Jener Damau Arroyo, a Spanish-born gunsmith, to make modifications on their PASAMs in order to improve their handling. The first modification (PASAM MOD-1), of which 101 were modified, received a metal frame extension welded to the magazine housing. It was fitted with a metal forward grip well ahead of the gun under the muzzle. The original grip was left alone, making it compatible with the wooden holster/stock. The second modification (PASAM MOD-2), involving 89 pistols, featured a similar frame extension, but the forward grip had wooden panels and was of different shape. The pistol grip frame used thicker rectangular wooden grips and had a 1. 5-foot (460 mm) "t-bar" metal shoulder stock welded to it. A metal frame attached to the receiver supported a rectangular wooden foregrip, taking pressure off the barrel. In both models, of course, the barrel was left free so as to enable it to do its short recoil during firing. For the record, 295 PASAMs were left in the original condition. It took standard detachable 10-round box magazines, although they can also take the extended 20- and 40-round magazines.