Within the Stochastic-GAS method, one-and two-body reduced density matrices (RDMs) can be stochastically sampled as for stochastic FCI or CAS wave functions. Those can be subsequently utilized to calculate orbital gradients, Hessians or within the Super-CI theory to variationally relax the molecular orbitals. This gives rise to Stochastic-GASSCF. As shown in the following, RDMs can also be utilized to calculate properties that directly relate to them, such as the spin expectation value. The Stochastic-GAS method has been implemented and has been made available in the open source NECI program. The Stochastic-GASSCF variant is available via the interface of the NECI code with the OpenMolcas chemistry software package. The remainder of the article is organized as it follows: In section 2 we summarize the key concepts of GAS, FCIQMC, and the original PCHB algorithms. In section 3 we introduce the novel GAS-PCHB method, and discuss in some details its performance. In section 4 we discuss three test case applications, that show how Stochastic-GAS can be applied to various chemical situations, and to understand the role of different forms of electron correlation mechanisms.