Recommended level and most importantly that learning period says 'Yes'. If it says 'Not anymore' means you are maxed. Make sure you look at all learning period on the gun.
Sorry, I asked my question in a wrong way.
Just to make sure that I don't screw up with weapons again, I just want to be sure to make it clear for myself.
I bought a Breer M2A when I didn't have max my Sollomate Opalo, back in the days - The Breer M2A was saying "Yes" but yet, my friend told me it was useless to use it, unless I'm maxed with that very Breer M2A.
So I started thinking about NOT using advanced guns before I have maxed those - Like right now, I'm thinking about buying a Breer M1a because I'm getting really close to it for being maxed.
So the question was more like... What is the purpose of SIB with MAXED/NOT MAXED weapon? Skill Increase Bonus makes me think about : When @ "Yes", they're giving you a bonus at gaining skill, but what is the best to do?
Let's take the Breer M2a by exemple, I'm far to max it yet, but what is the best way to gain skill actually? Opalo, M1a or M2a? Opalo is the only one maxed, but M1a is really close to it.
PS : I don't even have 2000 Rifle yet.