Tie the bungee into the nose cone first, then do your wraps. You can do it in "your" order first - but only to find the correctly lenght of the line. So, bascially do what you did in your pics and then mark where to tie the end into the hole. And then do it the other way around. The extra 30cm or so is just to be cut off.
Also, next time, better to post in the
sub forum for pneumatic spearguns under spearguns.
Also, while I hate to tell you this, you bought the smallest possible gun and power will be very limited. It’s basically for ultra closeup shots and nothing else. If there’s a way for you to return this gun then seriously consider that and get one 1-2 sizes up instead, which will be much, much more usable. A 70 is a very good starter gun with decent range and once you get an even more powerful gun you can keep the 70 for bad viz or hole hunting.
If you really wanna keep this gun, then rig it with mono as soon as you are comfortable with it. If you keep to a 1.4mm mono or less, you should feel quite an improvement over that thick nylon it came with. Personally, I would also get rid of the shaft with the interchangeable tip as they are super draggy and instead put a nice 7mm shaft on it. Others will prefer the 8mm (?) that came with it. But even with these two "upgrades" it still wont change the fact that your gun will not be that powerful. So be reasonable, practice restraint and don't take shots on fish that are not extremely close to you.
Finally, I checked your other posts and saw that you are looking for lobsters - if you got this small gun to shoot the lobsters then check your regulations to make 100% sure that is legal in your area. In many places around the world we are not allowed to shoot them. Hand grab them, yes and sometimes snaring. But no piercing.
Finally V2, I am not trying to be douchey but I also noticed you said that you are very new to freediving and don't like to go deeper than a few meters. To me that sounds like you are very, very much a beginner. Nothing wrong with that at all, we have all been there. But please make sure you educate yourself on how inherently dangerous this hobby is. Find a buddy, look for a club, take a proper freediving course - whatever it takes for you to not get into trouble.
Sent from my iPhone using Tapatalk