SEISMIC GUN ASSEMBLY FOR SHOOTING INTO A BORE HOLE

A seismic gun assembly comprising a barrel and guide tube assembly for delivering a projectile to the bottom of a bore hole with a non-line-of-sight section. The guide tube being either a large diameter guide tube or a tight fitted guide tube. The large diameter guide tube allowing the projectile to perform shallow angle bounces to reach the bottom of a non-line-of-sight bore hole. The tight fitted guide tube allows the projectile to ride the inner wall of the guide tube to reach the bottom of a non-line-of-sight bore hole. The projectile comprises an outer jacket and a frangible core. The seismic gun barrel assembly additionally comprises a fluid exclusion puck for preventing fluids from entering the guide tube, a suppressing collar for suppressing seismic noise, and a method for modulating recoil.