The 180-degree swivel-lever safety of the M1934/35 was cumbersome and slow to operate, being almost impossible to rotate with the gun hand.

[3] The frame grip angle was changed to allow more natural position of the shooting hand when pointing at the target.

The trigger was also re-designed to improve (lighten) the average weight of pull required to fire the pistol.

As the replacement for the M1934/5 in Beretta's compact/medium pistol line, the Model 70 integrated the M1951's takedown lever, guide rod system, slide stop, and magazine release button in the lower part of the grip.

Removing the magazine caused the slide to slam forward into battery, unless the operator engaged the thumb safety.

The follower hold-open was eventually replaced in Series 70 production with an improved dedicated slide stop, a feature again derived from the M1951 service pistol.

Later, in order to meet U.S. pistol import regulations under the 1968 Gun Control Act, a thumb shelf was added to the Model 70s left grip panel.

Later export (U.S.A.) models were equipped with grips featuring a prominent left thumb rest.

[2] The S version was introduced in 1977,[2] included a new magazine safety,[2][3] and marked the adoption of caliber .380 for the Model 70, to replace .32 ACP.