Firstly, I'd recommend you not to improvise what you're saying, but rather prepare at least some basic points you want to make on the sheet of paper and follow that. You will sound more proffesional and people will like the more densed content more.
Secondly disable hints (at least while you're making a video) because they are distracting attention.
Then, there's no such thing as "powerful ammunition", really. Lochnagar perhaps could be defined as one, but that's not the case here. It's never worth shooting a baloon with a gatling gun, the only supposedly valid option would be using incendiary ammo to start fire on a baloon, but there are many things that do the same more effectively.
"Big gun" is called Heavy Flak (Cannon)
"[pyramidion] is the only ship that [gat-mortar] tactic really works" - nope nope nope nope nope nope nope NOPE, it works on Pyramidion, Mobula, Junker, Spire and sometimes even Squid and perhaps even Goldfish (Flakfish with gatlings? It's...possible, I'd say)
You could say that Lesmok due to wide spread of bullets isn't always the best choice to shoot far targets (that's why we use heavy clip), and also that it increases the speed of the bullet (so it hits the target faster on the same range). Also worth mentioning is that heavy clip due to it's concentrated fire is good for disabling.
I may be wrong here but isn't 4th supposed to be written 'fourth'?
More of a personal note: reminder about subscriptions in the middle of a video is distractive and in my opinion is not in good taste, leave the subscription stuff to the end of the video.
I may sound rude but I'd recommend you playing the game more before you start making tutorials.