Maybe, but the constant external resistance of the barbell will not be very forgiving if you attempt to perform repeated partial repetitions through the sticking point. You will likely need to reduce the weight to successfully perform lengthened partials with the traditional bench press.  Using a machine with a well-designed resistance curve avoids this issue, as the machine applies less external resistance through the typical sticking point of the press. This allows for the use of lengthened partials at the end of a high effort set (as demonstrated in the How to Progress section). The machine also has built-in safety features to protect you in the event you take your lengthened partials past the point of failure.