Why Enclose the track?

Spearguns have either an “open” track or an “enclosed” track. Open track is pretty much just a slight channel or trough that the spear shaft rests in whereas an enclosed track wraps around the spear but still has an open top for the spear shaft teeth.

With an open track the shaft needs to be locked in the mech and then require the shooting line (mono) to wrap around the front of the shaft so it doesn’t just fall off the gun. With enclosed track this feature is not required since the track will hold the shaft in the gun.

An open track will allow the shaft to move or bend freely during the shot as the bands propel the shaft. Bands that are not balance side to side can slightly move the shaft side to side. Also, an open track will allow the shaft to bow under the force of the band as its firing. These factors can reduce accuracy. One must be careful how much band force is applied to the shaft due to the potential of bowing.

An enclosed track doesn’t have these issues. You can go higher power or band force with the shaft held in an enclosed track. One drawback is there is a bit more friction losses as the spear drags the track surfaces. Some also speculate there is a vacuum effect as the spear is leaving the track and the water takes its place. I’m not sure the real impact of this effect.

DRETCHEL guns almost always have an enclosed track made from poured epoxy and designed with color additives to personalize each design. It definitely adds more work to do the enclosed track but most agree its the way to go.