A speargun having a stock, a muzzle at a distal end thereof; and a pair of matching elastic tackles assemblies either side of the stock for tensioning a wishbone from the muzzle to a spear. Optionally, the speargun may have a second elastic tackle assembly disposed on the bottom of the stock. According to another approach, a speargun component kit may be provided to a user to attach to their own stock having a muzzle; a pair of tensionable pulley tackles having a line to attach a spear, to attach to the muzzle, and to attach to at least one pair of elastic bands at a second end; an adjustable anchor mount of the elastic bands to the stock, and a spear release mechanism.