Ohshiboom blank firing grenade (impact BFG) – Colour Shock V2 Colour Shock V2, complete with .209 primer base – this is the latest design. The OhShiBoom blank firing impact grenade has been designed from the ground up to be the most steadfast reusable BFG on the market. Compact and intuitive, this grenade has been made with care in the UK from top quality materials. The casing is machined from aluminium to keep weight to a minimum, the internals are silver zinc-plated case-hardened steel. This is a single-piece design (so no lost spoons) and the Oh Shi Boom impact grenade can be quickly re-primed with a £1 coin (or spent blanks); no specialist priming tools are necessary.