Properly Loading Your Speargun – Band Size, Load Assists, and More
Properly loading your speargun can be a challenge. There are a couple techniques and tools that make loading a speargun easier. There are also different material option of bands that can make loading your speargun bands easier or harder.
Proper Loading Technique
Most spearguns can be loaded using proper technique rather than brute force. Trying to load a speargun through brute force alone can result in some challenges. Loading a speargun requires a few muscle groups that are not the most common exercises in normal life. See this video on proper speargun loading technique for rear handle spearguns.
The band length is the biggest factor that makes a band difficult to pull back. That being said, your spear shaft won’t hit the fish hard enough to penetrate without the right length spear shaft. The optimal stretch for a speargun band is 350% stretch. The formula to find the length your bands should be is:
This formula applies to all the different diameter bands. Making your bands stretch more than 350% doesn’t dramatically increase the power you are adding to your spear shaft. Making longer bands reduces the power to the spear shaft. If you reduce the power of your bands too much you won’t be able to shoot through your fish.
There are several thickness band options available for your speargun. The thickness of the bands determines the amount of stored energy in the bands. 9/16” (14mm) bands store approximately 90 pounds of force per band. 5/8” (16mm) bands store about 110 pounds of force per band. 3/4” (19mm) bands store 130 pounds of force per band. The challenge with bigger bands is it takes that much force per band to load them. Some divers prefer to have a larger number of easier bands, other divers prefer one hard to pull band. Past injuries or surgeries may impact your choice on bands. Make sure your speargun is designed to accept your band diameter of choice before purchasing. Some muzzles may not be able to accept some larger band diameters.
Small ID Bands
In the past few years Small Internal Diameter (ID) bands have increased in popularity. The idea behind them is the bands have more rubber inside them, which adds more stored energy to smaller bands. This makes the bands a little harder to load than the standard ID bands. Many people feel their spear accelerates faster as a result of the smaller diameter bands.
Load assists are particularly helpful if you have had some type of shoulder injury or surgery. They are also beneficial for loading very long spearguns or roller spearguns. The idea is you can hook the load assist to the band’s wishbone and load the load assist to the spear notch. Then you can finish the band load with the band already partially loaded.
Some spear shafts can be customized to have additional loading tabs added further forward on the spear shaft. These are supposed to work in a similar way to the load assists, in that you partially load your speargun in order to get into a better position to complete the load. They are frequently called ‘cheater tabs’ because they make it easier to load the speargun. The term is is just so guys can give each other a hard time. In reality they help folks that have had injuries or surgeries that would otherwise keep them from properly loading their spearguns.