Abstract: Paired elastomeric elements, preferably made with silicone rubber, are separated by flat and preferably metallic separator elements which are parallel to each other when the elastomeric elements are not subjected to an external compressive load. The assembly of separator elements and elastomeric elements sandwiched therebetween in pairs is held between end plates intermediate a mass subjected to an external time-varying force, e.g. from an automatic weapon subjected to reaction forces from the projectiles being fired therefrom, and a support structure that is to be isolated from the time-varying forces. Each elastomeric element serves as both a spring and a damper, absorbing and dissipating absorbed energy to isolate a support structure from the full effect of the time-varying force from the weapon mounted thereon. The provision of elastomeric elements having different damping coefficients is particularly effective in eliminating the transmission of high frequency time-varying forces through the buffer unit.