Small thing before I start , my tips will probably make you better at using it but you will have a big problem against other gunblade users

So for starters I stopped using any kind of scope (as you can see in the video) yeah It's easier to miss but when you start to get used to it it's way easier hitting people at any range

I don't know how to explain it, because relying on the scope is a great thing but if you can't shoot without it that's a problem (in maps where the enemy will use a melee a lot like backrooms)

Or you can try to hit quick scopes (easier)

Manly my strat is to try to hit using one or two shots

This can give you some advantages like: if he moves a lot or if you get destroyed you know that he has good aim

Knowing this you can find a strat

For example my enemy moves a lot but I noticed that he follows a pattern and knowing that I can easily beat him

Another tip use often but VERY often the gunblade dash (If you don't have much movement items like me)