Abstract: The pistol is used for injecting through a hole a sealing product formed by a mixture of at least two solutions. It comprises a tubular injection system which is fed, notably under pressure, with each of said solutions, and which ends with an injection head capable of penetrating into the injection hole. The tubular system includes for each solution, an independent transfer conduit emerging from the end of the injection head, so that the mixing of the solutions is performed outside the injection head. Preferably, the first transfer conduit is a tube with a circular cross-section and the other transfer conduit(s) has(have) an annular cross-section, being delimited by one or several tubes arranged concentrically around the first transfer conduit.