The shock response of polymers is important for a number of commercial and defense-related applications, but it is difficult to obtain empirical shock response data over the wide range of preparations and aging conditions typically found in such applications. Ultrafast compression is useful to characterize polymer shock response over a wide range of polymer initial conditions due to the high throughput of this method. To establish greater confidence in ultrafast compression experiments and to characterize the detailed shock response of several variations in a single base polymer, the results of sub-nanosecond shock compression experiments in similar to 5 mu m thick layers of the polydimethylsiloxane (PDMS)-based elastomeric rubbers Sylgard-184, SE1700, and an unfilled, end-linked model PDMS network are presented. The results of conventional ultrafast shock etalon measurements to time-of-flight measurements for similar thickness layers of irradiated and unirradiated SE1700 are compared. Good agreement between the shock response measured by these two ultrafast shock methods, as well as consistency between ultrafast data and long time scale gas gun data is found. From measurements across a variety of PDMS formulations, a statistically significant variation in the shock response with the quasistatic elastic modulus is presented. Published 2018.