they arent quiet cuz its a 209 primer going off, very easy to shush tho and even if you did it out back or w.e most people would think its a firecracker

i have no remedies for the issue but another method of testing, try the PIP-9, those tend to be much better imo for real world testing and its just fun af to shoot 3DP ammo in your room. just dont hit the drywall, itll gouge tf out of it