Abstract: During rock drilling and blasting activities, stemming blast holes is to prevent high-pressure explosive gases from the holes, thereby enhancing the overall blasting effectiveness. Hence, it is imperative to investigate the dynamic mechanical properties of the stemming materials. In this study, impact compression tests were conducted on self-swelling cartridges (SSCs) using a split Hopkinson pressure bar (SHPB), aiming to evaluate dynamic performances across strain rate range of 20 to 65 s⁻¹. Test results indicate that the dynamic compressive strength of SSCs exhibits the following trends: it increases with increasing density of SSC, decreases with an increase in insertion gap, and follows an initial rise and subsequent fall trend with an increase in water absorption. The order of significance among these factors is density > water absorption > insertion gaps. SSCs exhibit a pronounced strain-rate strengthening dependence in dynamic compressive strength. Furthermore, both the compressive peak stress and peak strain of SSCs follow a well-defined quadratic upward trend with increasing strain rates. As the strain rate increases, the degree of fragmentation, absorbed energy, and dynamic increase factor exhibit an upward trend. Model experimental results indicate that, compared to cementitious stemming materials, SSCs can prolong the duration of gas explosion action. Therefore, SSCs are more suitable for high strain-rate applications such as blasting stemming and rock burst control.