Behaviour of a speargun with a novel muzzle Comportamento di un fucile subacqueo con testata innovativa

T. Ingrassia, M. Mucera, V. Nigrelli


The paper presents the results of a numerical and experimental investigation performed on a barrel
of a speargun equipped with two kinds of muzzle. In particular, a standard muzzle for speargun (having an
elastic propulsion) has been compared with an innovative one called ‘roller’. This new muzzle is equipped with
two rollers and special bands. The rubber bands, fixed at the lower side of the barrel, run through the rollers
and are engaged in suitable seats of the shaft. These bands are, therefore, longer than the traditional ones and,
consequently, with equal force applied by the diver, the roller speargun has a longer range. Thanks to the
particular geometry of the new muzzle, one of the front constraints of the elastic bands is moved to the lower
part of the barrel or the handle.
As a consequence, the scheme of the loads applied on the speargun remarkably changes passing from a standard
muzzle to a roller one. All that has a great influence on the level of deformation of the barrel and, consequently,
on the accuracy of the shot. Because of the low velocity of the spear (if compared with the firearms), in fact, the
accuracy of the shoot if strongly influenced by the barrel bending due to the forces applied by means of the
elastic bands...

Full Text: