The KWC Python 357 Revolver is one of the loudest and most powerful 2.5 inch revolvers out there. 1 BB is inserted into the tip of the 6 shells it comes with. You fit it into its speed loader, load the 6 rounds and off you pop!
The revolver is made out of metal to withstand the pressure the CO2 has to offer, expelling a BB at around 400 fps, which is extremely powerful for a revolver this short. It may not be the most practical revolver out there, but the material and its functionality will give it a sense of realism other revolvers do not have.